Whenever two or three MPs are gathered together, they will quickly move on to that fascinating topic. Who will be the next Prime Minister.? Assuming that this is likely to be a Tory, the odds changed today.

Philip Hammond is grey. As with Theresa May, there is an aura of well-raked gravel drives in the depths of the Home Counties. But that makes an obvious point. She is the Prime Minister. Not that she was convincing today. Before a Budget or Autumn Statement, Prime Minister’s Questions normally becomes a warm-up act, with a lot of knockabout. Jeremy Corbyn does not do knockabout. He always aims for moral seriousness, and today he succeeded. His attack was predictable. The whole country is trapped under a black cloud of austerity. The NHS is collapsing. The poor are dying. Mr Corbyn, an unrepentant Marxist, does all that well.

But any half-way competent Tory ought to be the master of the obvious refutations. There is a choice between the free market, with its imperfections, and the Soviet Union, with all its obvious perfections. Assailed by Jeremy Corbyn’s slightly bumbling earnestness, Mrs May displayed no mastery. She seems incapable of big pictures or generosity of spirit. Reverting to that unfairly maligned-region, the Home Counties, she sounded like the crackling of autumn leaves heading for the wheelbarrow in an upper-middle class garden. There was none of the size – moral, mental, political – that we should expect from a Prime Minister. It was much the best performance Mr Corbyn has given. Afterwards, a number of the boys were wondering aloud: ‘Is the girl up to it?’

That was after Mr Hammond had sat down. He did display mastery. It was clear that he had an absolute intellectual command, which allowed him to indulge in a few donnish jokes. There is an obvious point and a satisfactory point. First, Philip Hammond would never make a living as a comedian. Second, he would never try to. If anything, he underestimates his powers of wit. That is a fault on the right side.

It also brings us to Boris Johnson. He does not underestimate his powers of wit. Indeed, he thinks that they could carry him to the Premiership: Donald Trump, Boris Trump. If anything happened to Mrs May tomorrow, Liam Fox would be gagging to run. Others would gag him. David Davis would think that his hour had come. The clock would have other ideas. It would be too early for George Osborne, while shares in Sajid Javed are down eighty percent from a year ago (which makes them a buy). Ruth Davidson is not available. Jesse Norman and George Freeman have been under-promoted. There would only be two serious candidates: Boris Johnson and Philip Hammond. As this is a serious country, Mr Hammond ought to prevail.

But there is no vacancy.

As for the Autumn Statement itself, it was designed for accountants, not humans. Over the next few days, the big tax-accountancy firms will be digesting it for their clients. But if they are honest, they will acknowledge that Mr Hammond’s measures are at the mercy of events and rely on the haphazards of forecasting. It all comes down to economic growth: to the great waters of Europe and the narrow margins of Micawberism. The estimates are that Brexit will reduce the UK’s GDP by two and a half percent: one fortieth. The equivalent of Mr Micawber’s sixpence, that is margin of error stuff. The European economies are beset by uncertainty as is the world economy, courtesy of President-elect Trump.

Mr Hammond’s tone was reassuring. His measures were all sound. Any commentator who just sneers that the Chancellor should cut spending and cut taxes should be required to identify the cuts that he would make. The infrastructure investment will almost  certainly be helpful. That said, scrapping London’s cycle-lanes to improve journey times would make a more immediate contribution to growth. Those who expected excitement from Mr Hammond were disappointed. He was merely sound. That, too, was a fault on the right side.