Theresa May’s body language on leaving the European Council summit last night shows quite how much of a toll the past few weeks have taken on the Prime Minister. She looks exhausted. Now, you don’t have to feel sorry for May: she did, after all, decide to call the snap election that has proved to be her undoing - even though so many people thought she would be mad not to call it with the Labour party appearing to be so weak. But it is worth noting that the most important people in government - and the most important people involved in the attempts to keep the government together - are all totally exhausted and that this exhaustion inevitably has an impact on the way government works.

In the fortnight since the election result, Number 10 has lost key advisers including May’s top aides Nick Timothy and Fiona Hill. Their departure was the price of the Prime Minister hanging on, but it will have left her without some of the people she trusts the most: and May is not someone who learns to trust quickly. Key positions in Downing Street remain unfilled, and this means that those who are working there are working twice as hard in a job that is already famously demanding after weeks of an election campaign that will have sapped their reserves.

No-one works well when exhausted, not even people well-suited to demanding jobs. Exhausted people make bad decisions that make little sense outside the pressured, slightly mad world of Number 10. This might be why May’s first visit to Grenfell Tower made so little sense to everyone in the outside world who had at some point managed to reacquaint themselves with sleep and a perspective beyond the Downing Street gates. Things that hardly matter suddenly become huge obstacles in the mind of exhausted politicians and their aides: if you apologise for this then you’ll have to apologise for everything that has ever happened and therefore you can’t say sorry for anything ever. Or if you visit these disaster victims then they will be angry to your face, even though those outside the Number 10 bunker might conclude that allowing grieving, frightened people to be angry is infinitely more honourable than trying to hide from an awkward encounter.

Exhausted people don’t interact well with others either, growing snappy and irrational, which is perhaps why negotiations with the DUP don’t seem to be going very well at all. We now face the prospect of a vote on the Queen’s Speech with no formal confidence and supply agreement with the Northern Irish party. This won’t just be because of the imbalance between the canny negotiators of the DUP and the naive Tory team: there will also be a strand of tired irrationality to the proceedings. The hollowing out of Number 10 is also a factor in the delayed agreement.

It’s unlikely that anyone will get much rest any time soon. The instability of the government makes late votes and endless negotiating between different political factors more inevitable: whips will demand MPs stay on the estate at all times and may be far less sympathetic to requests for extra time with family or early finishes.

The only sort of exhaustion that is beneficial to May at the moment is that shown by her MPs, who are tired of fights and scraps and seem to fancy a summer of sleeping after three years of elections and referendum campaigns. This tiredness gives her a little time in her job, but the crushing nature of the past few weeks makes it much harder for the Prime Minister and her staff to do that well.