Weak Theresa May is destined to fail – but it may not be Brexit that brings her down

The British parliamentary system is ‘well adapted to human weakness: the feeblest prime ministers are soon removed, and even the strongest before long have to give way to new leaders capable of coping with changed circumstances’

The secret of prime ministers is that they are weak. This is a conclusion of Andrew Gimson’s wonderful portraits in his new book, Prime Ministers: Brief Lives from Walpole to May.

“We give them an impossible job and blame them when they fail to perform it,” Gimson writes. “The Prime Minister serves as a kind of glorified scapegoat. It notable how many of them are remembered, if at all, for a single failure.”

Their failure, however, does not mean that parliamentary government has failed: “For it is a system well adapted to human weakness. The feeblest prime ministers are soon removed, and even the strongest before long have to give way to new leaders capable of coping with changed circumstances.”

Gimson defends the parliamentary system as an elementary form of quality control: “There are very few complete duds in this book, for the Commons can detect a dud as soon as he or she begins to speak.

“For the same reason, it is virtually impossible for a criminal, or a demagogue, to become Prime Minister. Someone like Donald Trump could not get to 10 Downing Street. The Commons sees through, and will not tolerate, that kind of person.”

As Gimson says, three of the greatest failures, the Lords Bute, Aberdeen and Rosebery, failed because they had never sat in the Commons.

Even those who do succeed tend not to last long. The average time spent in office is just five and a half years. When Gimson finished his book in October, he did not know that Theresa May would still be in office by the time it was published.

But what are the qualities needed to succeed, even temporarily? Gimson opens the book with a list of 12, the first of which are courage, luck, hunger for power and eloquence.

By chance, students at King’s College, London, taught by Jon Davis, Michelle Clement and me, had a chance to ask Tony Blair that question when he came to talk to them on Wednesday. “Very thick skin” was his first answer.

He mentioned temperament, ability to deal with pressure and team-building, but the important thing was strategic vision: “The Prime Minister has got to retain this ability to lift the eyes of the country to the horizon. Otherwise you’re fighting trench warfare against your opponents day to day, but the country itself is not really moving.”

He thought it was “very hard” for modern prime ministers to do more than eight to 10 years, which was a coincidence because he lasted for 10. “People just get fed up, even if you’re doing a good job.”

But he was self-deprecating about it: “By the time I got into year nine, I really got the hang of the thing.”

He was also asked which previous Labour prime minister he thought he was similar to, and I don’t think it was mere vanity that prompted him to say, “None of them, really.”

Gimson writes that prime ministers “are so different from each other that it does not occur to historians to describe one of them as being the same as another”.

Yet there are some themes and patterns that emerge, from his survey of the lives of the 54 holders of the highest office in the UK.

If there is a lesson in history, it is that Theresa May is unlikely to last long, and that if she is remembered at all, it will be for a failure. But the failures are not usually foreseeable.

Who could have known that the popular Lord North would lose the American colonies? Who would have guessed that Anthony Eden, brilliant and experienced in foreign policy, would be disgraced by a foreign adventure? Or that Blair, domestic moderniser, would be remembered for a foreign war?

And if there is going to be a prime minister remembered for failing over Brexit, it is likely to be Cameron, who united his party on Europe, only to be brought down by it. Theresa May would have to make a terrible mess of our actual departure to be remembered for that. It is more likely that she will manage Brexit on mediocre terms, making the best of the instruction of the voters in the referendum, and then be blamed for failing at something else entirely.

One essential quality for modern prime ministers is, after all, the ability to win elections, and she has already been found wanting at that. As the Conservative Party approaches the 2022 election – if she has not failed by then – a failure will be contrived for which to blame her.