Boris Johnson’s refusal to budge on Brexit has backed him into a corner – and a general election will be the only way out

“Optimism is not enough.” That’s the view in Whitehall, articulated by one senior civil servant, of what is seen as Boris Johnson’s very thin plan for Brexit.

True, Johnson got a cheer from the studio audience at last night’s head-to-head ITV debate when he neatly hit back at Jeremy Hunt’s claim that he was “peddling optimism”. Johnson replied: “I think we need a bit of optimism.” Previously, he has spoken about using “positive energy” to break the Brexit impasse.

Civil servants think the main difference between Johnson and Theresa May would be what one called “basically, a change of style”. Last night, Johnson dismissed her (and by extension Hunt’s) approach as “managerialism” and “defeatism”. Officials are quietly preparing to offer PM Johnson the substance he lacks. Options include a much longer transitional period, an idea also under consideration in Brussels. It would not mean more “kicking the can down the road”, which Johnson has said would make the Conservative Party “kick the bucket”. He could claim the prize of getting Brexit across the line and then, as he has hinted, resolve the Irish backstop issue during the transitional period.

This would fit with Johnson’s desire for a “standstill” with the EU on issues such as customs to ensure a smooth rather than disorderly exit (Whitehall’s bottom line). The downside is that the backstop would still be alive – on paper, at least – in the withdrawal agreement, without which there would not be a transitional phase. But if Johnson managed to get off to a positive start with the EU – a big if – it’s possible that both sides would raise hopes the backstop would never be needed, as it would be overtaken by events such as a free trade agreement and technological advances to prevent a hard border.

Contrary to the myth peddled by Brexiteers, Whitehall is not an army of Remoaners mobilised to block Brexit. It is true that some parts of the machine, notably the Treasury, is worried about the economic impact, but it wouldn’t be doing its job if it wasn’t. The overwhelming majority of officials regard their political neutrality as an article of faith. Many have served successive Labour and Tory administrations without missing a beat; it is what they are trained to do.

With Johnson looking a shoo-in for the Tory leadership, there is some trepidation that he would come in determined to shake-up a machine that has “failed” to deliver Brexit. Last year he predicted that after the “car crash” of May’s Brexit policy, “the investigative teams will roam around trying to work out how the British civil service – this purring Rolls Royce – could have come such a cropper”.

The same lazy assumption about Remoaner officials saw May prematurely dismiss Sir Ivan Rogers, the UK’s ambassador to the EU, whose unparalleled knowledge of Brussels would have helped her avoid some of her early mistakes. We see the same attitude in the attacks on Olly Robbins, May’s negotiator, for doing his job – as she wanted.

The suspicion among some in Whitehall is that a Brexiteer was behind the spectacular leak of the unflattering diplomatic telegrams about Donald Trump sent home by Sir Kim Darroch, the UK’s now-former ambassador in Washington. Who benefits? Eurosceptics who want to prevent Sir Mark Sedwill, the cabinet secretary, or anyone else they brand part of a “Remain plot”, succeeding Darroch.

The civil service would try to steer PM Johnson away from an aggressive, Trump-style approach to the EU negotiations. Etched in the minds of officials are comments by Johnson about how Trump would “go in bloody hard” if he were handling Brexit. This time last year, he told a private meeting there would be “all sorts of breakdowns” and “chaos”, and that while “everyone would think he’d gone mad ... you might actually get somewhere”. Johnson’s view of Trump that there is “method in his madness” is anathema to many in Whitehall. It doesn’t do madness.

It might be Johnson who comes “a cropper” if he were to imitate his pal across the pond. Suspending parliament to force through a no-deal exit on 31 October, which Johnson refuses to rule out, would be straight out of the Trump playbook.

“It’s a non-runner; it would end in tears,” one civil servant told me. Johnson wants to keep all options on what he calls his very big table so Brussels gets a strong message the UK is serious about no deal and makes concessions. But his ability to prorogue parliament is open to doubt, as Wednesday’s dramatic intervention by Sir John Major shows. The former prime minister warned that he and others could seek a judicial review in an attempt to stop such a move.

There are fears in Whitehall that Johnson’s very tight, unrealistic deadline of 31 October, and repeated pledges to leave then “come what may”, puts him on a path to no deal and a clash with the Commons that will end in a general election. Officials will try to steer him away from it. But, as one put it: “The worry is that he has painted himself into a corner.”