DO not panic. That is the message from the UK Government. Brexit is going just fine, it says; the stalemate is on the verge of being broken; and Theresa May’s dinner with Michel Barnier and Jean-Claude Juncker was not – repeat not – a sign of the jitters but a regular meeting that had been in the diary for weeks. And, just in case you find yourself panicking anyway, Boris Johnson is on hand with a metaphor. The great ship, he says, is ready to go down the slipway and on to the open sea

But, as one EU source put it after the last dinner between Mrs May and Mr Juncker in April, the Prime Minister and her Brexiters must be living in a galaxy far, far away if they think the talks are going well or that they are anywhere near a breakthrough.

The Brexiters have also persisted in the view that, if the talks do fail and there is a cliff-edge, no-deal Brexit, then again, everything will be just fine. Arch-Brexiter John Redwood said this week that he was perfectly relaxed about the EU imposing tariffs and the UK would be able to trade successfully under World Trade Organisation rules.

Fortunately, back in the real world, we have the likes of Professor Anton Muscatelli, Principal of Glasgow University, to explain what is really going on. Whatever the Brexiters may have us believe, the fact that we are leaving the European Union will damage the economy – indeed, it is already doing so – but how we leave the EU is just as important, with a cliff-edge, no-deal Brexit the worst option. Already, the prospect of a Brexit of any kind has led to a number of banks announcing that they are relocating some operations and staff away from Britain and, according to Mr Muscatelli, if firms are forced to avoid a no-deal Brexit, the trickle will become a torrent.

The logic of Mr Muscatelli’s argument is sound. Businesses need certainty and, if there is any chance of a no-deal Brexit, they cannot wait until we go over the cliff – they need to act in good time and plan now to ensure that they are ready if the worst comes to the worst.

According to Article 50, Britain will be plunged into the no-deal scenario if the talks have not been concluded by March 2019, but Mr Muscatelli says the cliff-edge for businesses is actually early next year when their contingency plans have to be executed.

The financial services firms that Mr Muscatelli has spoken to have stepped up their plans so that they are ready to act in the next few months.

The flicker of hope is that there is still time (although not much) but it requires progress on Brexit soon. The bad news is that nothing the UK Government has done indicates such progress is likely, making what was once a scary story – a cliff-edge Brexit – a realistic prospect which the Opposition in the Commons has started to plan for.

The Brexiters will say “bring it on”. But in the real world, as those contingency plans demonstrate, we must expect what always happens when you go over a cliff: a rapid fall and severe injury.