One would never think, from Boris Johnson’s demeanour at Prime Minister’s Questions, that he had last night suffered a setback.

How ebullient he was, and with what gusto he set about putting fresh heart into his own backbenchers, while treating with studied civility, even affection, almost everyone on the Opposition benches except for Jeremy Corbyn.

The Labour leader complained that the proposed Brexit deal “clearly does damage the future of the Union”, by introducing customs checks in the Irish sea.

Johnson retorted that the Labour leader’s “sentimental attitude to the Union” was “a bit rich”, given Corbyn has spent most of his career “supporting the IRA”.

The blow was delivered with a magnanimous good humour which Corbyn must find infuriating. How does one persuade voters that this benevolent Prime Minister is in reality (as Corbyn and his friends believe) an evil maniac who is intent on grinding the faces of the poor?

The Prime Minister added that the Leader of the Opposition is the true threat to the Union, by proposing to spend the next year holding two referendums, one on Brexit and one on Scottish independence.

And he said of Corbyn: “I understand his visceral dislike of America and his visceral dislike of free trade.”

He is busy defining the opponent he will face in the general election as someone the British public cannot possibly support.

Aspiring novelists are advised to “show, not tell”, and Johnson frequently applies this maxim to politics.

Catherine West (Lab, Hornsey and Wood Green) asked about racism in football, and “why bigotry has currently been emboldened under the current government.”

Johnson responded with a vehement denunciation of racism in football, which must be stamped out at every possible opportunity. He had shown, not told, that he is no bigot.

He reminded his opponents that he is a formidable electioneer, able to move at will between the great issues of the day and petty local concerns, possessing a Dickensian ability to tell the truth by exaggerating it in a preposterous yet life-enhancing way.

“The crossing of the railway line at Suggitts Lane is never far from my thoughts,” he assured Martin Vickers (Con, Cleethorpes), who had put down a question about “transport infrastructure of northern Lincolnshire”.

Johnson dramatised that dreary abstraction by seizing on the Dickensian name “Suggitts Lane”, giving it a ludicrous national prominence which conveyed his understanding that to local people the railway crossing matters, and indicated to them they can rely on his wholehearted support in their efforts to get something done about it. How Vickers beamed.

Johnson has increased the pressure on the Labour front bench to help get his Brexit deal through, by showing them what they would face if they fought a general election on the issue.