Not one person qualified to do so - neither a practising barrister nor any Government counsel - has attempted to dispute Michael Shrimpton's conclusive opinion (published in a 27-page document of which copies are freely available) that the metric regulations are unlawful and unenforceable.

Therefore the claim by P G Crewdson, Cornwall County Trading Standards Officer (letter, Feb 18) that this opinion "is at odds with those of Government lawyers" is untrue. I defy him to produce an opinion, by a competent legal authority, that can prove Mr Shrimpton wrong.

If he cannot, then Mr Crewdson must apologise for accusing the British Weights and Measures Association of "a clear incitement to break the law" since it is in fact his own department's activities that are unlawful in seeking to implement these sham regulations.

For the same reason, not one council anywhere in Britain has yet dared to undertake a prosecution of any of the thousands of honest traders who continue to satisfy their customers by serving them in imperial measures. For the first appropriate prosecution would be treated as a test case to prove that the whole process of compulsory metrication was unlawful and must be repealed.

Will Mr Crewdson urge the county council to put it to the test in a court of law? If not, will he admit that the regulations are a 'dead letter' and may be safely ignored?

VIVIAN LINACRE

Director, British Weights and Measures Association