Boris Johnson thinks no deal will leave the country flush – the Brexiteers’ delusions know no bounds

The Tory party leadership contender wants to spend the money the chancellor wants to use to mitigate the worst effects of Brexit on tax cuts for the rich – while pushing through the most economically harmful Brexit of all

The long cast list of Conservative leadership candidates seems completely stoned. Not on some exotic substance that has sparked the greatest outpouring of contrition since Henry II allowed himself to be whipped by monks, but on Brexit. It is an addiction, with each new mind-altering inhalation demanding a harder and harder hit. So a no-deal Brexit will be through parliament by October, says the Johnson Brexit pusher. “Paff! Is that the best you can do,” swaggers back Dominic Raab, who seems completely off his head by now. “I will prorogue parliament and force it through.”

As hallucinogenic thinking goes it is up there with Keith Richards in the 1970s; the Stone later reflected that he could scarcely remember the decade.

But judging by Johnson’s attempted foray into economics, perhaps he is now closer to The Beatles “Lucy in the Sky with Diamonds”, so away with the fairies is he. He promises nearly £10bn of tax cuts paid for – wait for this, because it’s a cracker, as he might put it – from the Brexit war chest built up by the chancellor.

Yes, you read right: the war chest Philip Hammond has put aside to prepare for some of the damage that his colleagues threaten with Brexit. Johnson is proposing the very most damaging Brexit of all, so what can he possibly be smoking to imagine the Treasury will have one spare penny under his leadership left to fritter on tax cuts?

If Johnson somehow manages to force a disastrous no deal on a reluctant public the economy will be in freefall. We will be denied free access to the world’s largest market that takes almost half our exports, along with all third countries with which the EU has negotiated favourable trade deals. The UK would face an economic emergency to render the winter of discontent a happy hippy trip.

But it gets worse. Johnson claims he would spend this mythical £9.6bn on tax cuts not only for the wealthiest workers – obscene enough when the poorest still suffer from austerity – but the primary beneficiaries would be rich retired. Because Johnson’s plan is to claw back some revenue through National Insurance which the retired don’t pay.

Given that we are at historic levels of generational unfairness, this is (to reluctantly employ another Johnsonism) gobsmacking. It flies against the Lib Dem approach in coalition to incentivise work. This fantasy proposal rewards idleness. With our public services suffering from years of cuts it is hard to think of a more divisive policy to impose on a Brexit-riven Britain.

Even by Johnson’s standards its cynical. But this is all about wooing the 160,000 largely elderly Tory membership in the leadership race, not about the country. Well, Johnson did say “f*** business”. This is how he would screw the rest of the country. Under Johnson the very notion of responsible government would go to pot.

The tragedy? There is a very sober alternative, which I will flesh out as a candidate in our own Liberal Democrat leadership race. For if we stop Brexit there will be a Remain dividend. The money Hammond has been forced to squirrel away due to the determination of his Conservative colleagues to pursue Brexit could be invested to rebuild Britain.

And especially in “left behind” areas, many of which voted Leave. They have suffered the chill winds of automation, globalisation and the credit crunch. It is only right we invest in training, infrastructure and green technology here to revive their economies and – more important still – societies. Rather than a Johnson prospectus that would bring us economic ruin and civil unrest, this would help heal the terrible scars of Brexit.

So here is my plan: we use this money – Hammond has mentioned £15bn, Johnson mentions £26bn – that would have been spent to pay for no deal. And instead we use it to usher in a new period of prosperity.

I am working cross party to block Raab’s assault on democracy. I’m also exploring whether we could deliver a vote of no confidence in a Johnson premiership – odds might be improving after his latest “plan” – and then form a temporary national government to deliver a referendum on Brexit.

As Rory Stewart rightly says, Johnson is poisoning our bloodstream. But what no Tory candidate – even Stewart – can acknowledge is that Johnson is merely the crazed doctor injecting the toxic substance. The deathly drug itself is Brexit.

Ed Davey is the Liberal Democrat MP for Kingston and Surbiton