The Liberal Democrats have become the latest political party to join the populist “save the pint” bandwagon. However, on this occasion their action will not only preserve the use of the imperial pint as the only legal measurement unit for the dispensing of draught beer, but arguably it will also prevent government Ministers from allowing metric measures for draught beer in the future, even if only as an optional alternative to pints.

Pub owners wishing to stage Oktoberfest-style events, with litre-steins of draught beer, will continue to be prevented from doing so, regardless of the wishes of the Minister for Business and Trade.

The current legal situation

Bizarrely, for over 25 years, draught beer and cider, and milk in returnable bottles, have been the only goods that can be legally traded in the UK using old imperial measurement units. All other goods are required to be sold using metric units.

Whilst milk in returnable bottles can also be sold in metric amounts, draught beer and cider are unique in that they must be sold only in imperial amounts of ⅓ pint, ½ pint, ⅔ pint, 1 pint, and multiples of ½ pint.

On the other hand, beer and cider in bottles and cans, and milk in non-returnable bottles, are all required to be sold exclusively in metric units. However, there are no prescribed quantities for these goods, so containers with sizes of multiples of 568 millilitres (approximately one pint) can be used, and marked in supplementary imperial units, providing that the imperial marking is not more prominent than the metric quantity marking.

University of Cambridge study

A Cambridge study last year revealed the health benefits of reducing the standard serving size of draught beer from one pint to two thirds of a pint (379 ml), but that such a significant reduction would probably be rejected by the public.

UKMA’s proposal of an optional 500-ml serving size, in a lined “pint” glass could have formed the basis for a follow up study, but would have required prior ministerial approval. However, under legislation currently going through Parliament, such approval will be all but impossible.

The Product Regulation and Metrology Bill

The innocuous and technical-sounding title of the Bill that was debated in the House of Commons this week, belies its true nature.

On reading the text of the legislation, as originally drafted, there is little mention of Weights and Measures. The use of the word “metrology” also seems to be an attempt to obfuscate the Bill’s application to this purpose.

This Bill is another piece of legislation in the style of the previous Government’s Retained EU Law (Revocation and Reform) Act 2023, which is often colloquially referred to as a “Henry VIII powers” Act. It is essentially a framework designed to remove the customary process of Parliamentary approval for new legislation. Instead, the Secretary of State for Business and Trade is given the power to introduce regulations unencumbered by Parliamentary scrutiny.

When this Bill passes, Parliament will relinquish all responsibility for future regulations introduced within its scope. Given that the relevant Minister can be a member of the House of Lords, Parliament could be voluntarily surrendering its sovereignty to an unelected bureaucrat.

It seems that fears among some MPs about the nature of these future regulations led to a concern that the current use of the pint might be done away with. Indeed, in the House of Lords debate on 5 March, the word “pint” was mentioned 60 times.

This is where the change to the Bill concerning the pint comes in.

On 5 March 2025, an amendment to the Bill (Amendment 38A) was introduced in the House of Lords by Liberal Democrat Lord Fox, which was accepted by the Government. The clause in the Bill as amended reads,

(4) The Secretary of State may not make regulations under this section to prevent or restrict the use of the pint in the marketing of —
(a) draught beer or cider, or
(b) milk in returnable containers.

The amendment was described as a “safeguard” to preserve the use of the pint. However, this clause arguably also prevents the Secretary of State from introducing metric measures for draught beer in the future, even if only as an optional choice for landlords, as this would necessarily reduce the use of the pint.

The Bill passed its 2nd Reading in the House of Commons on 1 April 2025 by 303 votes to 110, and is now in its Committee stage.

This Bill as amended is another regressive step in the UK’s painfully-slow metrication process.

Speaking at Foreign Office questions, Conservative former minister Sir Edward Leigh said:

“I’m a simple soul so I trust the Foreign Secretary completely. Will he assure me that nothing in the Product Regulation and Metrology Bill … will in any way nullify Brexit by limiting our deal to make our own decisions on regulation and to conduct our own free trade deals? And above all, as a Great British patriot, will he assure me that nothing in the Bill will allow any minister to ever abolish the most glorious of British symbols – the Great British pint?”

The Labour Foreign Secretary, David Lammy replied:

“Can I assure the right honourable gentleman that the Great British pint is safe under this Government.”

With all three major parties now actively supporting the exclusive use of the imperial pint for draught beer, we are a long way from the situation in 1904, when 333 MPs were in favour of fully adopting the metric system for all official purposes.

References

The Product Regulation and Metrology Bill
https://bills.parliament.uk/bills/3752

House of Lords debate – 5 March 2025
https://hansard.parliament.uk/lords/2025-03-05/debates/64F82F9F-EC44-42D3-9CC6-7D5A59270654/ProductRegulationAndMetrologyBill(HL)

House of Commons debate – 1 April 2025
https://hansard.parliament.uk/commons/2025-04-01/debates/298723EA-059D-4682-8B74-C64D603A8F20/ProductRegulationAndMetrologyBill(Lords)

David Lammy says British pint ‘safe’ as MPs debate measurement legislation – 1 April 2025
https://www.independent.co.uk/business/david-lammy-says-british-pint-safe-as-mps-debate-measurement-legislation-b2725292.html

British pint to be protected in law as concession leaves Tories flat – 5 March 2025
https://www.standard.co.uk/news/politics/government-tories-british-conservative-liberal-democrats-b1214941.html

The hidden-away bill charting a course back to Europe – No-one wants you to look at the product safety and metrology bill. And there’s a really good reason for that. – 14 February 2025
https://iandunt.substack.com/p/the-hidden-away-bill-charting-a-course

On 18 March, the Times reported that NICE (National Institute for Health and Care Excellence) had opened a consultation on an updated version of their general guidance document in which it proposed that millions should have an annual weigh-in to fight obesity. These weigh-ins would take place at doctor’s surgeries and will be aimed at those who have certain conditions including diabetes, arthritis and heart failure. The consultation runs until 15 April 2025. [Ref 1, 2, 3]

The Royal College of GPs has however warned that since services are already over-stretched, any such campaign needs to be properly funded.

While it is not up to the UKMA to comment on the practicality or otherwise of the proposal, it is prudent to point out that in the long run, unless people’s weights are communicated in kilograms, the exercise is likely to run into problems.

The medical profession has been recording patients’ weights in metric units for a number of decades. In 2010 the Department of Health, following a review by the Local Authorities Coordinators of Regulatory Service (LACORS) issued the “Estates and Facilities Alert EFA/2010/001” in which it states all medical practitioners were required to use CE certified Class III or Class IIII weighing devices (as appropriate). It is mandatory that such devices be calibrated in metric units only with displays in imperial units prohibited. Prior to that some medical establishments had been using bathroom scales that had been purchased from high street outlets, and which did not undergo regular calibration. [Ref 4]

Patients have every right to be told their weights. There is no official guidance to medical practitioners as to what units they should use when communicating with their patients. As a result of the persistent use of imperial units in the press, many patients expect medical practitioners to communicate their weights to them in “old money” (aka imperial units). Some practitioners oblige but other suggest that the patient look up the conversion for themselves.

Once many readings have been taken, it might well be appropriate for the medical practitioner to comment on changes over time. While it might appear to the casual reader that conversion from kilograms into stones and pounds is a simple matter, there are hidden complications. How many people are conversant with equating “half a stone” with “7 pounds”? (On a live broadcast, Lord Parkinson showed that he was not able to do so.) Using the language that the patient understands also puts pressure on the practitioner as to whether to use stones and pounds or stones and fractions of a stone or, for those who prefer metric units, to use kilograms.

Another bugbear is printing out details of changes in a person’s weight over time. One of the classic ways of displaying data is using a graph. Many graphics packages have outputs that are designed to be incorporated into data handling packages. Most such packages are decimal based (apart from handling dates and times) and as a result such packages cannot produce decent graphs with stones and pounds on the y-axis. A cheap work-around might be to display stones and decimals of a stone but this would be a sign of shoddy design and would only serve to cloud the results further. The only real solution is to use a decimal-based system of units which, in the UK, means kilograms.

If His Majesty’s Government is minded to getting the most out of the exercise, it makes sense for them to encourage the use of kilograms by all sectors of the population. A YouGov survey taken in 2022 showed that 72% of the British population weigh themselves using stones and pounds with 24% using kilograms. The survey also showed marked variations across different socio-economic groups. The highest take-up of metric units was amongst the younger age groups with 44% of those in the 18-29 age group using metric units as opposed to 11% in the 70+ age group. There were also marked variations across the country’s regions with 40% of Londoners using kilograms as opposed to 28% of Scots and 18% of those who live in the Midlands or Wales. The use of kilograms was most prevalent amongst LibDem supporters (33%) as opposed to 14% amongst Conservatives while 27% of EU Remainers preferred metric units as opposed to 13% of Leavers. [Ref 5]

In South Africa (where I lived until 1978), the government took the lead in promoting metrication by, amongst other things, banning the sale of measuring devices that displayed imperial units (with or without metric equivalents). This approach might also have worked in the UK during the 1970’s, but in today’s political climate such an approach would not work. If the British Government is to get the most out of an anti-obesity program, it needs to take the lead in ensuring that medical practitioners and patients use the same units to communicate with their patients as they use amongst themselves and that language is unquestionably the metric system.

Although the general public has not been invited to partake in the NICE consultation, it would be appropriate if one of the outcomes of such a consultation is that a program be put in place to ensure that medical professionals and the general public all use the same system of units as each other. The UKMA as an organisation is of course neutral as to the practicality of annual weigh-ins.

References

1. The Times – March 18, 2025 – Millions will have annual weigh-in to fight obesity.
2. NICE information document: https://www.nice.org.uk/news/articles/annual-bmi-checks-recommended-for-adults-with-long-term-conditions
3. NICE Consultation: https://www.nice.org.uk/guidance/indevelopment/gid-qs10183
4. Weighing device notice: https://www.nss.nhs.scot/media/5709/efa-2010-001.pdf
5. YouGov survey: https://d3nkl3psvxxpe9.cloudfront.net/documents/YouGov_-_Metric_vs_imperial.pdf

In a follow up to an article last year, about the occasion in 1904 when Parliament came close to fully-adopting the metric system, we consider one of the possible consequences of this failure.

A metric campaign leaflet, produced by the World Trade Club in 1919, presents evidence in support of a hypothesis that the First World War would have been 2 years shorter if the UK and USA had both been on the same measurement system as the rest of the Allies at the time, i.e. metric.

It is a horrifying thought that millions of lives might have been lost as a direct result of the failure of efforts at the turn of the 20th century to adopt the metric system in the UK and the USA.

    click on the image to access the pdf

The evidence presented in the leaflet, Keep The World War Won, is thought-provoking, although largely anecdotal. It attributes what it calls the “much-vaunted efficiency of the German military forces” to metric standardisation throughout its educational, industrial, commercial and military structure.

The Allies, on the contrary, it states, had at first no such standardisation and interchangeable uniformity.

The metric standards of France, Italy, Russia, Rumania, Greece, Belgium, Montenegro, Portugal, Serbia, and the rest – 23 fighting allies and 7 who had broken off diplomatic relations with Germany, including the nations of Central and South America; that is to say, some 30 of the allies – were not interchangeable with the British and American weights and measures. Even British and American measures were not interchangeable with the result that great and grave difficulties, long costly delays, interfered with their co-ordination and efficiency promptly to aid their allies.

We know that the German Kaiser counted upon this confusion for 2 years’ delay in the war preparations of the allies. We know that he expected to crush France and gain world power before the allies, thus handicapped, were really ready to fight.

All of this begs the question, “Would the First World War have even happened at all, if the UK and the USA were fully-metric countries before 1914?”

The leaflet considers this possibility, citing President F.O. Wells of the Greenfield, (Mass., USA) Tap, Die, Machine Tool Co.,

… the German Kaiser would not have dared declare war if America and Britannia had been standardized on metrics when the Germans adopted the system exclusively in 1871. In that event they could instantly have co-operated with one another and with all their allies, co-ordinating the supplies and munitions from every part of the world. President Wells insists that this lack of standardization and of coordination lengthened the war 2 years.

The leaflet continues,

The French Minister of War, Millerand, said that Kitchener’s volunteers promptly arrived in France, splendid battalions, but unarmed – there was plenty of ammunition for them, but their guns were not standardized to use it.

Joseph P. Colter, who acted as Hoover’s representative, and Dwight W. Morrow, member of J.P. Morgan Co., with a distinguished service record during the war, say in June Atlantic Monthly, page 804: “Allies each had individual types of munitions … The lesson of co-operation was forced upon them, but not until the third and fourth years did they finally admit that not only all their strength, but the joint use of all their strength, was essential.”

The World Trade Club

The leaflet, Keep The World War Won, was one of a number of campaign leaflets produced by a San Fransisco-based organisation called The World Trade Club.

The US Metric Study Interim Report, published in 1971, describes the World Trade Club as, “not a club at all but was, rather, the cloak for a publicity campaign whose sole purpose was to secure legislation adopting the metric system in the U.S.”.

A letter accompanying the leaflet urged readers to lobby “Legislators of U.S. America and Britannia” to “secure the early world-wide use of meter-liter-gram”, by filling in the supplied postcards.

The leaflet itself, printed only one year after the war, has an anti-German tone and contains a number of dubious assertions, such as its claim that imperial weights and measures were “Forced Upon Us by Germans”. Presumably, this was done in an attempt to exploit anti-German sentiment in the wake of the devastation of the war.

The leaflet’s front page also asserts that James Watt “thought his greatest work the Watt Measuring System, whose 3 principal units became METER-LITER-GRAM”. Whilst James Watt is on record as proposing the adoption of a universal decimal-based pound, and was in favour of the foot being redefined such that one cubic foot of water would have a mass of exactly 1000 ounces, it is a stretch to claim that he invented the “meter-liter-gram” system.

If the producers of the leaflet were keen to emphasise the anglosphere influence in the development of the metric system, it is unfortunate that they didn’t concentrate more on British scientists’ contributions to the electromagnetic units of the metric system, or their role in producing the prototype kilogram. It would seem that they were also unaware of John Wilkins’ significant contribution in practically inventing the “meter-liter-gram” system himself, in 1668.

Nonetheless, it is noteable that, whatever period of history is researched, there seems to have been no shortage of effort being made to persuade legislators to adopt a universal decimal system of weights and measures.

On the consequences of failing to fully adopt the metric system before the First World War, it would be interesting to know if this has ever been the subject of an authoritative study.

References

U.S. Metric Study Interim Report
https://www.nist.gov/pml/owm/metric-si/us-metric-study-report

A History Of The Metric System Controversy In The United States
https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nbsspecialpublication345-10.pdf

Further reading

House of Lords votes in favour of full adoption of the metric system
https://metricviews.uk/2024/02/23/house-of-lords-votes-in-favour-of-full-adoption-of-the-metric-system/