Any Prime Minister who takes over mid-term has to contend with a certain set of problems. Liz Truss will wish she had been propelled through the front door of No. 10 by the momentum of a general election victory.

The first difficulty is that you have no personal mandate. This doesn’t just affect your relationship with the electorate, but your own MPs too. Boris Johnson benefitted from a sense that he was a winner, which made MPs more prepared to trust his judgment. Liz Truss will have to go that much further to persuade MPs of her political calculations. It also means MPs will be more jumpy if the polls are bad.

Next, you don’t have much time. Truss, rightly, emphasised the importance of delivery in her acceptance speech. But while a PM normally has four or five years to make good on their agenda, Truss will have just two before she has to go to the country. This complicates things. Take the temporary VAT cut Truss supporters have floated. Cut VAT for a year now, and you’ll be having to increase it – boosting inflation – just before an election.

Anyone who takes over in mid-term also has to handle a predecessor from their own party. John Major had Margaret Thatcher making trouble, Boris Johnson has had to deal with Theresa May making clear of what she thought of his behaviour on the Northern Ireland protocol, the Downing Street parties and explaining why the Rwanda policy couldn’t work. But these problems will be nothing compared to the mischief that Johnson could cause. He will be back to the role that he performed happily for a decade, being the Tory gadfly: grabbing the news agenda just when their successor would most like them to shut up. Truss clearly intends to handle him carefully: look at the praise she heaped on him in her acceptance speech. But as his comments on fracking last week showed, Johnson won’t bite his tongue on the issues he cares about.

The final problem with taking over in mid-term is that you only get the job because things are going wrong. If everything was working, the Prime Minister wouldn’t be changing. Truss starts with the Tories behind in the polls and a series of inter-connected crises about to hit the country.

The opportunity for Truss is that the crises mean the country is paying attention to politics in a way that it usually doesn’t: it wants to know what the government is going to do. This gives Truss a chance to show the voters who she is and what she plans to do as Prime Minister.