Silliness is abroad in the UK. Some are arguing in favour of a looser monetary regime. I responded to this two weeks ago (“Britain must not cut loose its anchor”, May 15). Others are even muttering in favour of joining the eurozone, now celebrating its 10th birthday. Even my colleagues on the Lex column argued last week that the UK was close to meeting the economic tests for joining. The only obstacle to entry Lex could find was political.

Lex is wrong. Whether the UK meets arbitrary tests at a particular moment is irrelevant. What is right today may be wrong tomorrow. If a country is to join the eurozone, its people must be willing to cope with the consequences forever, however unpleasant they may sometimes be.

True, at present exchange rates, entry looks more plausible than for the past 12 years. The implied rate of the old D-Mark against the pound was 2.46 on May 23, well below the rate at which sterling was put in the old exchange rate mechanism in 1990. The real effective exchange rate measured by JPMorgan is 7 per cent below its average since the beginning of the 1980s. At present rates, adoption of the euro looks reasonable.

The remainder of this column can be read here. Comment from our expert panel appears below.

Read the debate - contributors so far include Willem Buiter and Andrew Smithers.