Wimbledon fortnight brings back happy memories of growing up in that pleasant suburb. But the recent news that the leading pretender to the Conservative throne was told by his girlfriend to “get out of my flat” stirs a particular memory: of the number of offenders brought before the courts who would be described in the Wimbledon Borough News as being “of no fixed abode”.

It was therefore a stroke of genius for Private Eye to put a picture of Alexander “Boris” Johnson outside No 10 Downing Street with the caption “I really need somewhere to live.”

One of the many troubles with a man whom most people I know regard as unfit to run a whelk stall, let alone a country, is that the term “no fixed abode” also applies to his policies – and what are laughingly called his principles.

The man’s unsuitability for office was demonstrated to all during that debate with rival Jeremy Hunt last week when he treacherously refused to support the British ambassador to Washington and, in effect, forced Sir Kim Darroch’s resignation.

There is an old joke that “every time that fellow opens his mouth, some damned fool speaks”.

Johnson’s betrayal of one of our leading diplomats was just the latest in the list of charges against him. He was of course one of the leading figures behind the falsehoods perpetrated during the referendum campaign. More recently his refusal to rule out a no-deal exit, and menacing threat to prorogue parliament, have compounded the economic damage being inflicted on this benighted country.

The idea that these threats are part of a cunning bargaining strategy to force our European partners to give him whatever he wants is laughable. What is not laughable is the daily procession of news items about companies that are essential to our economy either relocating abroad or cutting back on their operations in this country.

The fact is that Johnson’s approach has aggravated the uncertainty that has been undermining business confidence and having serious consequences on the value of sterling. I doubt whether even his Brexit supporters are happy with the exchange rates they face for the summer holidays.

His budgetary plans are so wild that he undermines any Conservative arguments about the budgetary dangers of a Labour government

Johnson’s malign influence was manifested in his widely quoted remark “F— business” and in the way Hunt was, astonishingly, prepared to say during his campaign that if firms went to the wall and people were made unemployed this was all in the interests of some higher good!

Hunt, supposedly a Remainer, moved dangerously near to Johnson’s “hard Brexit” nonsense, with the exception of being more flexible on the exit date. Some Remainer!

I am still hoping that some skeleton will emerge from a cupboard to floor Johnson’s ambition. What most people regard as more likely is that his reign will be mercifully short. The predictable chaos of his prospective tenure of No 10 is brilliantly captured in the play Brexit, by Robert Khan and Tom Salinsky, which I was lucky enough to catch at the King’s Head in Islington. A glorious hour of satirical sanity.

It has come to something when the chancellor, Philip Hammond, sees his Treasury days as numbered and is already planning to oppose a Johnson government from the backbenches. He has plenty to oppose: not only Johnson’s disgraceful fooling around with no deal and the possibility of proroguing parliament, but also his wild budgetary plans – so wild that he undermines any Conservative arguments about the budgetary dangers of a Labour government.

Hammond began the process of choosing the next governor of the Bank of England, but goodness knows how Johnson will handle this – one of the most important posts in the country, just as the managing directorship of the International Monetary Fund is one of the most important economic-policy jobs in the world.

Never slow to put himself forward, George Osborne, the high priest of the austerity religion, has indicated to the Financial Times that he would like to succeed Christine Lagarde at the Fund. However, the FT has given him short shrift and states: “A stronger British candidate, if available, might be former premier Gordon Brown, who rallied world leaders to act jointly on stimulus during the 2008 financial crisis.”

I agree. Even the IMF has had second thoughts about shortsighted and often self-defeating policies of austerity.

Although Britain played a key role in the formation of the IMF, we have never supplied a managing director. The nomination is now presumably within the gift of Johnson and whomsoever he appoints as chancellor. They should act on the advice of the FT.