A general uniformity of Weights and Measures is so obviously desirable in every commercial country, in order to the saving of time, the preventing of mistakes, and the avoiding of litigation, that its establishment has been a fundamental principle in the English construction from time immemorial, and it has occasionally been enforced by penal statues, and by various other legislative enactments.

Report from the Select Committee on Weights and Measures, 1862

In this country a standard of uniformity existed before the conquest. It was enacted in the time of Richard I, and declared by Magna Carta, that there should be one weight and one measure throughout the realm. In more recent times, committees and commissions have been appointed to inquire into the practicability of introducing a more simple and uniform system of weights and measures, as well as a system of decimal coinage.

The full report is available on the DTI website

Report of the Committee on Weights and Measures Legislation, 1950

This report chaired by E.H. Hodgson included the following conclusions.

The metric system is a closely defined and universally recognised system under the guidance of an international body. The imperial system is a conglomeration of units which form a rough whole. In Great Britain there are five different systems of weight and three of capacity. The Commonwealth bases the value of the units on Imperial Standards kept in London, but the U.S.A. defines its yard and pound on the International Metre and Kilogramme. The advantage of the metric over the imperial system is that it is entirely decimal, and being coupled with the decimal system of coinage, it makes for ease in calculation.

The Government should take steps in concert with the Commonwealth and U.S.A. to abolish the Imperial system of measurement and replace it by the metric system over a period of 20 years.

The full report can be seen on the bopcris web site

Final Report of the Board of Trade Committee on Consumer Protection, 1962

A uniform system of weights and measures, nationally used and enforced, is plainly part of the basic vocabulary of consumer protection.

1972 Government White Paper on Metrication

Paragraph 6

Progress to metrication cannot be a haphazard affair, left to individual whim and decision. If that were to happen it would cause confusion throughout industry and would present untold difficulties to the consumer. It is in everybody's interest therefore to ensure that (the change-over) takes place in a well-ordered and properly regulated manner.

Paragraph 10

To attempt to keep imperial units for the individual shopper while industry was on metric would be both confusing and costly. It would also deny us the very real savings to be gained when turning over completely to metric.

Paragraph 102

The nation must consider the costs of not going metric. These include the cost of continuing to operate two systems. If the United Kingdom were to retain the imperial system, while at the same time having to use metric to an increasing extent for international trade, British industry would be less efficient and less competitive and higher costs would be cumulative. This would have repercussions on the standard of living and we would burden ourselves with an economic handicap.

The full report is available here in PDF format