After becoming Prime Minister in July 2016, Theresa May aspired to be a transformative leader comparable to Clement Attlee and Margaret Thatcher. Even before recent events, that possibility had been extinguished. The loss of the Conservatives’ hard-won parliamentary majority destabilised the government, drained Mrs May of confidence, and shattered her authority.

Today, an enfeebled Prime Minister presides over the most discredited British cabinet in recent history. On 1 November, Michael Fallon resigned as defence secretary after admitting inappropriate behaviour towards women. He could not, however, resist adding pompously that he had “fallen below the high standards that we require of the armed forces” (as if he could have survived in another cabinet post).

As the New Statesman went to press, Priti Patel, the International Development Secretary, appeared likely to join Mr Fallon on the backbenches. After claiming that she had informed the Foreign Office of a summer trip to Israel (during which she held formal meetings with Prime Minister Benjamin Netanyahu and other senior politicians), Ms Patel was humiliatingly forced to admit that “this was not the case”. Mrs May did not learn of the meetings until more than two months after the event. For good measure, the International Development Secretary suggested that part of the UK’s foreign aid budget could be diverted to the Israeli army. Such flagrant breaches of ministerial protocol have made her position untenable.

Ms Patel’s hubris and ineptitude is rivalled by that of Boris Johnson. True to form, he this week embarrassed himself and his country by stating that Nazanin Zaghari-Ratcliffe, an imprisoned British-Iranian woman, was “teaching journalism” in Iran, rather than being on holiday as she claimed, when she was arrested. His error has potentially condemned her to five more years of incarceration.

To compound Mrs May’s embarrassment, her closest cabinet ally and de facto deputy, First Secretary of State Damian Green, is under investigation for alleged sexual harassment and the possession in his office of “extreme pornography”, which he denies. The situation would be comic were it not so serious for the stability of the governance of Britain.

For all these troubles, there is much talent and good thinking being done on the Conservative benches. Among the impressive and industrious backbenchers worthy of promotion are foreign affairs select committee chair Tom Tugendhat, Helen Whately, Johnny Mercer, Heidi Allen and Kemi Badenoch. Yet for fear of further destabilising her fragile premiership, Mrs May is unable to reshuffle her cabinet, promote fresh talent or command confidence in her leadership. And so the Tory ship slowly sinks.

A government of such low repute would be alarming at any time. But Brexit – the greatest challenge any administration has faced since 1945 – makes it all the more damaging. Having invoked Article 50 perilously early, ministers have since spent more time negotiating with one another than with the EU. The cabinet’s divisions have left Brussels bewildered as to Britain’s intentions.

Leave supporters often accuse individuals and institutions – Bank of England governor Mark Carney, Chancellor Philip Hammond, the BBC, the civil service, the liberal press – of undermining and even “sabotaging” Brexit. But, too often, the Brexiteers have simply undermined themselves.

The time and effort absorbed by EU withdrawal has left the government incapable of addressing the UK’s long-standing economic and social problems. Indeed, it is making them worse. Real wages have fallen for the last six months owing to the Brexit-linked spike in inflation. The chaotic implementation of Universal Credit has condemned some low-earners to destitution. After years of excessive austerity, public services are buckling under the strain of increased demand. Mrs May’s government once promised to ease the plight of the “just about managing”. In the event, it has proved incapable of managing itself.