By Colin Talbot

Boris Johnson might be having an easy ride to the Tory leadership, but his first few weeks in Downing Street are likely to be very different. Wariness of the former London Mayor on the Tory benches and outright hatred on the Labour benches means it'll be a baptism of fire. These are the mechanisms open to those who want to take him on hard.

Day one

Assuming he wins, Johnson is expected to be called to the Palace and invited to form a government on the afternoon of Wednesday July 24th. Theresa May will conduct her final PMQs and go straight to the Palace to offer her resignation to the Queen. She will also advise her on who to summon to form a government.

Before that happens, a 'Golden Triangle', in the words of historian Peter Hennessy, will have met to advise the monarch on what she should do. It will consist of the Queen's private secretary, Edward Young, the prime minister's private secretary, Peter Hill, and the Cabinet secretary and head of the civil service, Mark Sedwill.

There's a chance Johnson will be immediately faced with the loss of his working majority. Some Tory MPs have threatened to resign the whip if he's elected. Some estimate there could be as many as 12 in this hardline rebel faction. If so, and even with DUP support, the majority is gone.

If the Queen were advised by either May or the Golden Triangle that Johnson could not command a majority in the House of Commons there is an immediate crisis.

Does she call on Johnson to form a minority government and wait to see what happens? Probably, but not absolutely certainly. It might depend on how many Tory MPs defected, for example.

Despite the warnings, this remains an unlikely scenario. The rumours in Westminster suggest that few, if any, of them are prepared to take this drastic action immediately. And even if they do, the instinct of the 'powers that be' will be for a smooth transition, so it's more than likely Johnson will be called to form a government anyway.

No-confidence

Technically, there is no need for a vote of confidence in the new prime minister. And practically everything's been done to avoid one.

The Commons rises for the summer recess the day after he becomes PM, leaving almost no time for the Opposition to put down a motion under the Fixed-Terms Parliament Act and get it debated before the break.

Labour could try and delay the recess to allow this to happen and the Speaker, John Bercow, would probably enable it, but so far they've shown little inclination to try and force an immediate vote.

The only other possibility is that the Queen makes it a condition that Johnson puts down a motion of confidence in himself immediately to prove he can command a majority in the House. But that is unlikely.

The House of Commons will return for just over a week at the start of September before going into recess again for another three weeks for the party conference season. At this point Labour could move a vote of no-confidence. Will they try it then? Again it seems unlikely. It would mean scuppering their party conference to clear the decks for an October general election.

After that their next chance is October, when parliament returns - just weeks ahead of the Article 50 deadline.

Losing a no-confidence vote

Whether it's July, September or October, the consequences of a lost no-confidence vote are dramatic. Johnson would have 14 days to go back to House and get a positive vote of confidence. He could try all sorts of ways to do this – for example forming some fresh arrangement with other parties. If he was really desperate, he could even offer the SNP a referendum on independence. Who knows?

This period is awash with the potential for the Monarch to become embroiled in party politics.

The wording of the confidence motion is: "That this House has confidence in Her Majesty's Government." It's not a possible government, but "Her Majesty's Government". This implies that either it remains Johnson or someone else who the Queen has already called on to form a government.

Theoretically, that means the Queen (in reality the Golden Triangle) could call on someone other than Johnson to form a government before the second vote of confidence. But this would be utterly without precedent and it's hard to see how it could happen in practice.

All the talk about a National Government, or a minority Labour government taking over, is also perilously unlikely. The 'powers that be' would rather let the clock run down to a general election being called automatically after 14 days than risk involving the Queen in such a risky venture.

It's hard to know which way things will break. But we can conclude something from the fact the British political calendar and the Article 50 calendar collide within weeks of each other in that mid-October period: That's the most likely time for it all to hit the fan.

November general election anyone?

Prof. Colin Talbot is co-director of Cambridge Policy Labs and Emeritus Professor of Government at the University of Manchester.

The opinions in Politics.co.uk's Comment and Analysis section are those of the author and are no reflection of the views of the website or its owners.