You know how it is: you've had a great summer holiday and then someone makes a stupid remark on the journey back and by the time you get home, no one is on speaking terms.

Theresa May had a good summer on the whole – Downing Street was in control of the agenda for much of the silly season, even if that came at the cost of saying silly things about a big clock. Her new spin chief, Robbie Gibb, has done a good job of getting much of the friendly press on side, at least if you measure that by the number of articles talking about how good the new operation is. She's even strong enough to think about a wide-ranging reshuffle, with new jobs for Jacob Rees-Mogg and Jonny Mercer contemplated, according to the Times' Matt Chorley.

But the PM's ill-advised declaration that she intended to stay on and fight another general election was a reminder that May, rather like the Arsenal defence, might be able to put together the appearance of serenity on occasion but is only ever a minute or two from an unforced error.

Now that MPs are returning to Westminster, with a looming fight this week over the legislation formerly known as the Great Repeal Bill, the risk for Downing Street is that there are many more unforced errors to come.

The message from the top – vote with May or British capitalism gets it – has the advantage of appealing to Conservative MPs' newfound terror of Jeremy Corbyn, but it has also got people's backs up, report Henry Mance in the FT and Jessica Elgot in the Guardian.

The good news for the government is that thanks to the Fixed Term Parliaments Act, they can lose any number of defeats and carry on regardless – what constitutes "a confidence vote" is sharply limited and comes with the option of a do-over within a fortnight. The bad news of course is it hugely increases the leverage of both the DUP and Conservative backbenchers.

For May personally, the other worrying cloud on the horizon is that the briefing wars over who, exactly, is to blame for the party's current predicament have been given a new lease of life this weekend. The Mail on Sunday's Simon Walters got hold of extracts of a memo wrote by Lynton Crosby warning that a snap election was a "huge risk". The full memo then made its way to Tom Newton Dunn over at the Sun, showing that actually it was all Crosby's fault, really.

The danger for May is, whatever people might say in an attempt to rehabilitate themselves, everyone knows that the folks at Crosby Textor and the senior team at CCHQ were essentially unchanged from 2015, and they didn't go from worldbeaters to clowns in just two years. Any honest post-mortem will eventually bring fresh criticisms of the PM: and with a series of books coming out about the contest, that argument isn't going away anytime soon.

May returns from the summer with a position that looks surprisingly strong. But the dream of a significant reshuffle and a period in which she can rehabilitate herself might struggle to survive the reality of life without a majority at Westminster.