The United Kingdom is a country governed, in large part, by convention —but in the heat of the Brexit debate, those conventions are beginning to evaporate. The Speaker of the House of Commons overturned long-standing procedure to limit Theresa May’s room for manoeuvre. The opposition used a humble address to the sovereign to force the publication of the government’s full legal advice on the withdrawal agreement, though the convention is that such advice is confidential. Parliament then impinged on the executive’s crown prerogative powers by passing a law dictating how the prime minister must behave at an EU summit.

Under May, Downing Street sighed at such behaviour but grudgingly accepted it. Boris Johnson and his team have a different response. If their parliamentary opponents want to push the constitutional boundaries, then they’ll do the same. The personal motto of Dominic Cummings, Johnson’s senior adviser, is ‘with a pirate, a pirate and a half, with a gentleman, a gentleman and a half’.

As we now know, Johnson would not resign if he was defeated in a confidence vote, as most would expect him to. Instead, he would — as the fixed-term parliaments act allows — use the following two weeks to try to put together a majority. If he could not do that, he would go to the country and fight a general election after 31 October. The talk in Whitehall is that the election could be on the day after Brexit, 1 November, which would mean the UK would leave the EU during the election campaign.

Given that an exit date of 31 October is already in law, there’s logic to this position — but critics cry foul. They argue that during an election campaign, a government shouldn’t take any decisions that bind the hands of its successor. They would almost certainly challenge any attempt to try to leave the EU by default. One Tory campaign veteran predicts that this autumn will see ‘an election and a Supreme Court fight over whether we can leave or not’.

Downing Street’s strategy has ensured those who want to try to block Johnson from pursuing a no-deal Brexit will feel obliged to act as soon as parliament returns in September. This increases the importance of the G7 Summit in Biarritz at the end of this month — the first face-to-face meetings between Johnson and Jean-Claude Juncker, Donald Tusk, Angela Merkel and Emmanuel Macron. I understand that Johnson will be happy to talk to EU leaders at this summit and that ‘a serious offer would be taken very seriously’. However, if the EU sticks to its position that the withdrawal agreement cannot be reopened, then the No. 10 view is that there will be nothing to discuss on Brexit.

If that summit passes off without any indication that the negotiations are going to restart, then it will be clear that no deal is the most likely outcome. At that point, the anti-no deal forces in the Commons will act and, given that Johnson’s working majority is down to one, they may well succeed in bringing the government down. Inside No. 10, there is pessimism about their ability to survive such a no-confidence vote. They don’t, however, believe that their opponents will be able to agree on an alternative prime minister. One confidant of the Prime Minister tells me: ‘It is not in Corbyn’s interest to back some caretaker PM. It would create a centrist, Remainer party in parliament.’

The campaign that would follow would be a thoroughly unpredictable affair. We have never had a nationwide, four-party general election before.

Regardless of how much he says he doesn’t want one, Johnson has been preparing for an election from the moment he arrived in Downing Street. His first speech emphasised Brexit, more resources for the NHS, recruitment of 20,000 more police and increased education funding. The language in that speech was Johnsonian, but the substance of it could have come straight out of a focus group. The latest Ipsos Mori polling shows that voters’ top four issues are Brexit, the NHS, crime and education.

Conservative Campaign Headquarters is being placed far more directly under Johnson’s control. Isaac Levido, the highly regarded new director of politics and campaigning, has been told to get the party election-ready. Ben Elliot, the new co-chair, is tasked with bringing the money in — the party is desperately hard up and Elliot has the connections to bring in cash fast. At the same time, the Tories will learn from Vote Leave on data and other modern campaigning techniques. In the past three years, Cummings has been a frequent visitor to Silicon Valley and has spent a lot of time thinking about what politics can learn from tech. Expect those lessons to be applied in any campaign.

A 1 November election would mean it took place straight after Brexit day. It falls on a Friday rather than a Thursday but I am told that this isn’t a problem — it is just another convention that elections take place on Thursdays. If the UK had left the EU, it is hard to see what the Brexit party’s campaign pitch would be; Johnson would have succeeded in his plan to put them back in their box. On the other side, anti-no deal forces would have to decide whether they now wanted to go back into the EU, which will feel like a more extreme position once the UK has actually left, or simply reopen negotiations as soon as possible.

An election like this would be dominated by Brexit, and that would cause problems for Jeremy Corbyn, who has attempted to maintain strategic ambiguity on the issue. This worked very successfully for him in 2017. In 2019 it could be his downfall.

An election on the first day of a no-deal Brexit is risky for Johnson too. Whatever disruption there was at the borders would be on TV screens as voters went to the polls. Others would question if it was right for the government to delay the vote until straight after such a nation-defining moment, and the pound would be sinking.

Few things are certain right now, and no one could be confident in predicting how an autumn general election would unfold. But that is where we appear to be heading.