It couldn’t happen to a nicer bunch of fantasists. Worried that the government was not making enough preparations for the possibility of no deal being reached in the “negotiations” with the other 27 members of the EU, the voluble Brexiters within and without the cabinet called for evidence.

They have got it, in spades. The so-called impact assessments for no deal are, quite simply, horrifying. They were underlined recently by the Bank of England governor, Mark Carney, who rightly drew attention to the messages coming through loud and clear from business, trade unions, the City and, not least, food suppliers, road hauliers, ports and airports.

Now, of course, when they have got what they asked for – namely, attention to the possibility of a cliff-edge Brexit – the Brexiters don’t like it and yell “project fear”.

The governor was good on this too. Having pointed out that the possibility of no deal was “uncomfortably high”, he reminded the Brexiters that the pound had indeed crashed after the referendum, by some 17%. British holidaymakers are lucky now if they can receive €1.10 to the pound at the better places. As for those dreadful airport money changers, I saw 94 cents to the pound being quoted the other day. Just imagine what further damage crashing out of the EU would do to the currency.

Moreover, the British economy has already moved backwards, from being the fastest-growing economy among the leading EU countries to the slowest. The Bank calculates that the referendum and the prospect of Brexit have lopped up to 2% off gross domestic product.

My suspicion is that the MPC only raised interest rates the other week to give it scope to lower them again

Now, it has been suggested that the man or woman in the street might well wonder what GDP losses have to do with people like them.

The answer is: more than they might think. Slower growth affects the standard of living throughout the economy. And interruptions to the “just in time” flow of fresh food from the continent would hit people where it hurts most.

The pre-Brexit economic damage would have been even greater if the Bank of England had not pulled out the stops, kept interest rates down and boosted the liquidity of the financial system. Indeed, my suspicion is that the monetary policy committee only raised interest rates the other week to give it scope to lower them again if the worst happens. Already, in preparation for a crisis, the Bank has presided over a tripling in the amount of capital the banks have in reserve, and increased the liquidity of the system by several times this multiple.

It is not as if there are not enough economic problems surfacing without the added threatened catastrophe of Brexit. The Office for Budget Responsibility’s fiscal sustainability report for July is replete with warnings of the problems caused by a drastic drop in the growth of the nation’s productive potential. It is difficult not to conclude that this has been caused by the cumulative impact on confidence and investment of the austerity programme introduced by George Osborne. The OBR states baldly that, “broadly speaking, the fiscal position is unsustainable if the public sector is on course to absorb an ever-increasing share of national income simply to pay the interest on its accumulated debt”.

Only the deluded Brexiters imagine that Brexit would ease the nation’s financial problems. Those financial institutions planning to relocate on the continent – some are doing so already – are not exactly going to add to this nation’s tax revenues. As for May’s attempt to suck up to the Brexiters – it has been one sop to Cerberus after another – the OBR notes: “As regards the ‘Brexit dividend’, our provisional analysis suggests that Brexit is more likely to weaken the public finances than strengthen them over the medium term, thanks to its likely effect on the economy and tax revenues.”

If there is hope amid the chaos, it must surely be that the mounting evidence of the self-harm involved in Brexit will produce a change in the public mood.

In a fascinating letter to the Financial Times on 1 August, Robert A Rogowsky, professor of trade and economic diplomacy at the Middlebury Institute of International Studies at Monterey in California, suggested that “responsible leadership in London should reveal the cost of Brexit and get a proper ballot in place to confirm that British voters are willing to pay for it”.

He gives the example of how the voters of Alaska changed their minds about moving the state capital when faced with the true costs.

Remember that haunting song It Happened in Monterey? Well this idea comes from a different Monterey, but I like it.