Theresa May

That is the measure of the poverty of the prime minister’s ambition, and let me be quite clear that, even if she goes for a customs union, there will be no prospect of any sunlit uplands. It will take us back almost half a century to the bad old days before we signed up to the European project and we were ridiculed as the “sick man of Europe”.

All the privileges won for us in the intervening years by such tough negotiators as Margaret Thatcher will be casually discarded, along with the coveted seat we had at the EU’s top table. Love her or hate her, it is important to acknowledge how Thatcher had championed inward investment from Japanese companies who could use our membership as a springboard into Europe. We have been in receipt of £46bn to date from 1,000 Japanese companies that chose to operate in the UK – and never expected they’d find themselves outside the EU’s customs union and having to set up shop elsewhere in Europe.

Pressing the customs union button does not address, either, the vexed issue of the Irish border, which will mean that the DUP won’t be able to sign up to it and the spectre of a return to the Troubles will once again loom large. It will not by any stretch of the imagination amount to “taking back control” as the UK would have no voice and no veto on agreements or tariffs. To all intents and purposes, a customs union would equate to no deal for the services sector, which accounts for 85 per cent of our economy.

And I’m not talking just financial services, as the sector includes retail, transport, distribution and food services, as well as other service-dominated businesses. Just a 10 per cent shift in banking and finance transactions would reduce government revenues by about 1 per cent, which works out at £7.9bn. To put this into context, this is almost 10 per cent of the £88bn that the government annually spends on education.

So why is no one in government seriously disputing the fact that the customs union option would be significantly worse than the bespoke deal we presently enjoy with the EU? A line from Shakespeare occurs to me: “O Judgment! Thou art fled to brutish beasts, and men have lost their reason!”

A customs union option could probably pass through parliament and there would then be the two-year transition period, but what then? Will whoever it is who succeeds May in 10 Downing Street not be tempted to tear up the non-legally binding political declaration containing the customs union? New leaders like to put their own imprimatur on proceedings. This could all too easily amount to hell postponed in the form of no deal two years down the line.

Should Number 10’s new tenant be Boris Johnson, there is no way, incidentally, that May could put a so-called “Boris lock” on any of the arrangements that she is now trying to put in place. Why? Because, constitutionally, no government or parliament may bind the hands of a future government or parliament.

May has said that the only alternative to a customs union is leaving the EU with no deal on 12 April. The Brextremists talk with ill-disguised menace in their voices about the “consequences” of May defying them and denying them their unicorns. But, make no mistake, no deal is still a real and present danger, which is the worst case scenario for our police force, health professionals, intelligence services, farmers and manufacturers. It could also mark the end of the United Kingdom – as the SNP and all those on the island of Ireland emphatically say: “Not in our names!”

With a choice of bequeathing two profoundly grim legacies to her successor and the country, May will have no spring in her step as she travels to meet first Angela Merkel then Emmanuel Macron to beg them for a short extension to Brexit on the dubious grounds that her talks with Labour are going swimmingly and likely to result in a positive outcome that will pass through parliament.

The emergency European summit follows in Brussels, when it is by no means inconceivable that the fine print of any extension will be taken out of her hands and dictated by the EU 27, as that is what realpolitik now means. There are already complaints in some quarters of the EU that Brexit is proving to be an unacceptable drain on resources and time as the trading bloc needs to focus on other pressing issues. As on official told me in Luxembourg last week: “We have to decide whether we should amputate the UK before it infects the rest of the EU with its madness.”

I understand of course that people just want Brexit to be over. People are desperate, depressed and exhausted – including our representatives in Parliament. Yet how unfair and irresponsible it is that they are expected to make decisions that will affect future generations – who never voted for this – in these fraught circumstances. In the words of Ralph Waldo Emerson, things are now in the saddle and they are riding mankind.

Allow me, if I may, to be completely candid in these, the final hours of this Brexit nightmare. There never were any sunlit uplands, no easy deals, no prospect ever of “taking back control” that would not have left us worse off than we are now as influential members of the EU. And, for those who just yearn for it to all end, let’s be clear that no customs union or no-deal scenario will put an end to the row about Brexit. Neither will allow our lawmakers and civil servants the calm they yearn for to look after our country and solve the deep-seated problems facing almost every aspect of our national life.

It breaks the hearts of all those of us who love our country – no matter how we might have voted almost three years ago – to see the great British lion vanquished and manacled in this way by circumstances, and, yes, small-minded, self-serving individuals. The great irony of all of this is that lion will have to look on, muzzled and enfeebled, in the years ahead as the EU sets about reforming itself and making it the union that realises the dreams of its founding fathers and becomes what all of us wished it to be.

No longer the lord of any jungle, the UK will, meanwhile, have to limp towards far-flung countries to try to seek help, but they are more likely to seize the opportunity to exploit our manifest weakness. I end my admittedly very depressing inaugural column with a single word: if. That is a big if, but it could yet save the union, our reputation, our future as a great trading entity and quite possibly our lives. That is if May accepts that there is – and always has been – a third option. And that is to revoke.