“The question is,” said Humpty Dumpty, “which is to be master – that’s all.”

Which is to be master – the Commons or the Government? That is the form the question took today, and since it goes to the heart of whether there is any point having a Parliament at all, the Speaker ruled it must take precedence over the debate on the European Union Withdrawal Agreement.

Sir Keir Starmer opened from the Labour front bench. His manner is about as unlike Humpty Dumpty as it is possible to imagine. From a  physical point of view, the Attorney General, Geoffrey Cox, is more like Humpty Dumpty.

The night before, Cox had brushed aside with majestic self-certainty the demand by the Commons that the Government publish the legal advice he  hadprovided to the Cabinet on the Withdrawal Agreement.

Now Cox, who reached the Chamber a few minutes late, had to sit in silence on the Treasury Bench and hear why the Government has got this wrong.

Sir Keir spoke slowly, setting out to build with impassive deliberation a case which would vanquish by virtue of its impregnable logic.

He was heard with respectful silence as he said: “The Government is wilfully refusing to comply with an order of this House, and that is contempt.”

He agreed with “the Member for North-East Somerset” – Jacob Rees-Mogg – that the Attorney General’s claim to be acting in the national interest was “not good enough”.

And he wondered “why on earth”, if the Attorney General feels so so strongly about the matter, he had not voted against the motion in the first place.

The answer to that question is that the Conservatives, fearing they might be defeated on the Opposition motion when it come up on 13th November, decided instead to abstain, as they have got in the habit of doing on inconvenient Opposition motions.

The Attorney General had the night before indicated that he had nothing to do with that decision: “It appears he was not asked,” as Sir Keir observed.

Andrea Leadsom, proposing for the Government that the whole subject be referred to the Committee on Privileges, could not match her opponent’s lawyerly gravitas, and referred to the Commons as “the mother of all parliaments”, when as any schoolchild should know, England is the mother of parliaments.

Sir William Cash (Con, Stone) gave a closely reasoned speech calling for “full disclosure” of the Attorney’s advice. He contended that the public interest in having that advice far exceeded any  public interest in keeping it confidential. He wished, for example, to know if the Attorney had advised that there is danger of the Withdrawal Agreement being declared “invalid under the Vienna Convention”.

Jacob Rees-Mogg said “the national interest is better served by serving the interests of Parliament than the convenience of the law officers”, and warned that when in power, the Conservatives should “defend the rights of Parliament for the occasion when we will not be”.

The Leadsom amendment was defeated by 311 votes to 307, and the motion put up by Sir Keir and his allies passed by 311 to 293.