Boris Johnson will steer Brexit Britain onto the rocks – the mutiny of sensible Tories is our only hope

A cunning rat leaves a sinking ship. Yet it’s a striking feature of today’s Conservative Party that so many are scrabbling to stay aboard their listing vessel instead.

Amber Rudd and the ever versatile Matt Hancock have even converted to the cause of a crash-out Brexit, despite previously warning it would be the economic equivalent of scuttling your own fleet at Scarpa Flow.

In a miraculous combination of rodent dexterity and selective amnesia, Michael Gove has discovered Boris Johnson has the character to take the ship’s helm after all. And tens of thousands of Ukip immigrants have hopped aboard to gnaw at the hull, to force Johnson into ever more undeliverable Brexit promises.

Fair play then to Guto Bebb, the one Conservative to date who has chosen to throw himself overboard, declaring himself unable to take any more. Who can blame the poor fellow?

The question is, how can those other Conservative MPs still in contact with reality remain in a party committed to closing down parliament and ditching the Irish backstop, as Johnson now demands – a course that can only lead to the ship floundering on the rocks?

You know madness has taken hold when it’s down to Liam Fox to be the voice of reason in reminding Johnson of Brexit realities. Previously, Fox’s main purpose was to tell soothing bedtime fairytales to Brexiteers (a deal with the EU will be “one of the easiest in human history” to negotiate, he famously said). Now he has to explain to our next prime minister that a UK-US trade deal might prove a tiny bit tricky. Fox’s entire career has been as spokesperson for some underexplained Transatlantist project, to make the UK even more subservient to America. Yet even he now says to Johnson: “Woah, hold on there, as prime minister you will actually be expected to look after the interests of the UK.”

Even Fox now seems to understand the fiendish complexity of Brexit.

Here’s just one example. Johnson reportedly plans to declare his contempt for the EU by making his first foreign foray to Washington to secure a UK-US trade deal. That would almost certainly make the Irish backstop unworkable, because chlorinated chicken and all could not only flood the UK but the entire EU without a hard border. But has Johnson even considered whether such a trade deal, following a no-deal Brexit and its likely hard border, could get through congress where Irish interests carry weight? I merely ask the question.

An alternative Johnson ruse – I struggle to call it a “plan” – is to extend the transition period until technology renders the backstop unnecessary. But this is pure Boris in Wonderland, because technology is not a solution. Even if “max fax” could calculate complex supply chains of major companies, the EU has already said it will not accept a system of legalised smuggling into the customs union.

You don’t need to be a John Maynard Keynes to understand that if Britain leaves the European market, a border will have to be put in place – and that would break UK obligations in a treaty lodged at the United Nations. A treaty struck after the loss of 3,600 British lives to guns and bombs in our own country.

It is hard to see how any traditional Conservative can remain in a party led by an anarchist of the right like Johnson. Conservatives used to like presiding over functioning economies; leaving without a deal, according to every serious economist, throws a grenade into the Treasury.

And yet, the Conservative leadership duo are engaged in a macho arm-wrestle to establish who would deliver the most economically catastrophic Brexit. Rather than heeding the warnings of the lighthouse, these wannabe captains are going full steam ahead into danger, having locked us all in the hold.

Mutiny is now our only salvation. Midshipmen and midshipwomen in the Tory crew now must do their patriotic duty: given their party is finished as a home for rational debate, yet remains in power, they must join with the rest of us to try to grab the wheel.

I am confident several will join the Liberal Democrats. Several may follow Guto Bebb. Those that stay must now fight to stop a Johnson no-deal Brexit from within.

As we peer into the mist and choppy waters ahead, two things seem clear. First, the poster boy of the Brexit movement will soon be in charge: there can be no accusations of betrayal now. Second, even with Johnson as prime minister, there is really only one way out – a Final Say referendum.

Liberal Democrats were denounced as cranks when we first argued this. But even Johnson will find as HMS Brexit threatens to wreck us all, a second referendum is the only life raft left.

Sir Ed Davey is the Lib Dem MP for Kingston and Surbiton