The Prime Minister combined magnanimity, the taking of the widest historical views, and a high seriousness which he rarely ventures to employ, with an undertone of irascibility.

He wished to sound, indeed to be so reasonable that any other reasonable member, from no matter what part of the House, could agree with him.

But he also expressed the hope, with a touch of ire against Sir Oliver Letwin (Con, West Dorset) and anyone else who might hope to prevent or delay this, “that we will indeed be allowed to have a meaningful vote” today.

The Prime Minister remarked later that his Right Honourable Friend the Member for West Dorset is “actuated by the best possible intentions”, and again, the undertone of irascibility was detectable beneath the tact and the friendship.

Boris Johnson was lucid. He was not going to get drawn into unnecessary arguments, unnecessary provocations, but no one could mistake the choice he was framing: vote for my deal, or defy the people.

He observed that British membership of the European Union has always been “half-hearted”, and has been discussed “in almost entirely practical terms”.

He could not remember anyone calling for a federal Europe: that argument had been “simply absent from our national conversation”.

Here was a fierce thrust at his opponents: they do not follow the logic of their position: even they do not really believe in a United States of Europe.

He spoke of “the eternal need for Britain to stand as one of the guarantors of peace and democracy in our continent”.

His language did not sound high-flown. He sounded entirely sincere about this, and entirely sincere in his desire to carry the whole of Parliament with him.

Nor, he insisted, does anyone in the Chamber believe in lowering environmental standards or the protection of workers’ rights.

Jeremy Corbyn proceeded to launch exactly that charge against this administration: “the Government cannot be trusted and these benches will not be duped”.

It is the duty of the Opposition to oppose, but Corbyn was unable to avoid sounding petty as he did so.

Soon he was threatening us with “chlorine-washed chicken”. Not for Corbyn the taking of wider views. He accused Johnson of abandoning his promise not to have a border down the Irish Sea, and concluded that “you can’t trust a word he says”.

Johnson replied in sorrow rather than in anger. He confessed that he was “a little disappointed” by Corbyn’s tone: “I had thought he might rise to the occasion.”

Tony Blair could not have occupied the moral high ground with greater aplomb than the present Prime Minister brought to the task.

As with Blair in the old days, there were occasional flashes of humour, a rueful recognition that some members of the House might find his elevated rhetoric tiresome, but also a tenacious determination to remain in this lofty and defensible position.