The Brexiteers have lost the economic argument and deep down they know it.

Week after week the statistics and the day-to-day experience of ordinary people are demonstrating that the promise that Brexit would be good for the economy, or at least do no harm, has proved false.

The slump in the pound is driving up prices for all imported goods, and households are feeling it in their pockets. It was argued that a weaker pound would boost the competitiveness of UK exports.

The slump in the pound is driving up prices and households are feeling it in their pockets

This, on the face of it, could have proved correct. But now it is becoming clearer that even this silver lining has failed to materialise.

Trade figures last week showed our deficit widening as exports of goods fell by almost 5 per cent.

The realisation that a Brexit boom is a nonsense is also reflected in the terms of public debate. A few months ago Brexit believers tended to persist in arguing it would boost the UK economy.

In February Boris Johnson said: ‘With every day the clouds of doom and gloom we heard last year become more and more distant.’ It is hard to imagine that claim being made today. A recent survey found that many, but far from all Brexit voters believe significant economic damage would be a price worth paying to leave the EU.

This is at least a coherent position (though we have yet to see what control we do actually regain). It is not, however, the argument that was made to the British public. The warnings of Project Fear, were exaggerated. But the claims that Brexit would not hurt the economy were just plain wrong.

RAIL travellers will see fares rise by well over 3 per cent over the coming year thanks to the sharp rise in the Retail Prices Index, and several reports last week highlighted the fact that student loans are pegged to this measure of inflation too.

But RPI is no longer regarded, even by the Office for National Statistics, as the best measure of inflation.

It no longer has status as an official national statistic and instead the benchmark measure for rising prices is the Consumer Prices Index.

CPI, although also rising rapidly, is markedly lower than the RPI figure.

Governments and public bodies should not change the statistics they use without good reason, it can smack of choosing the figures you want to suit yourself. But given that the nation’s best statisticians now set little store by RPI it is surely time to consign it to the dustbin.

We have enough trouble as it is with price rises outstripping pay without driving them even higher than reality by using a flawed measure.