Who is doing what to whom? Has Sir Keir Starmer, leading for Labour on the Brexit Bill, forced the Government to give ground?

Or have ministers cleverly drawn Sir Keir into their architecture of power, where he will find he has become a valued pillar of the regime, unable to move because of the sheer weight of masonry resting on his shoulders?

David Jones, leading for the Government on Day Two of the Bill’s Committee stage, opened his remarks to Sir Keir by saying, “I’m grateful to the Secretary of State.”

This was flattering, for it suggested Sir Keir is already a member of the Government. And in his slow, measured, unpartisan tone, Sir Keir does indeed sound like a man who can be relied on to run things in a sensible way, not some agitator who wants to stir up a revolution.

Mr Jones proceeded to give Sir Keir what Sir Keir has been asking for, namely the promise of a vote on the Brexit deal before the European Parliament gets a vote.

Some us have trouble keeping up with the Joneses, and realised we had not listened carefully enough to the start of the sentence, so were not sure exactly what the minister had given away.

But Sir Keir knew what was going on.”This is a huge and very important concession,” he said, but in such an authoritative and untriumphalist way that he did not seem to be crowing.

Anna Soubry, who was sitting beside Ken Clarke on the Nottinghamshire Tories for Remain bench, addressed Sir Keir as “my Right Honourable and Learned Gentleman – I nearly said Friend”.

The late, great Frank Johnson used sometimes to write about the Dinner Party, a body whose influence and membership transcend the trivial distinctions suggested by the words “Conservative”, “Labour” and “Liberal”.

The Dinner Party, to which not only Sir Keir, Miss Soubry and Mr Clarke belong, but also such luminaries as Nick Clegg and Ben Bradshaw, is just now feeling particularly energised.

As Sir Keir put it, “We all have an obligation to bring the country back together.”

It is therefore doubtful whether members of the Scottish National Party can join the Dinner Party, as they still want to lever the country apart.

Alex Salmond, for the Nats, made some grudging remarks about wanting to see Mr Jones’s concession in writing. The Dinner Party regarded this as unsporting: what a member of it has said, he has said.

Sir Keir did, however, warn that “the timing is critical” – the timing of the vote, that is. Mr Jones rose to clarify matters. To our relief, various eminent people, including Hilary Benn, had been unable to keep with with the Jones, and wished him to repeat himself.

Mr Jones declared: “This will be a meaningful vote.”

So that’s all clear, though Dominic Grieve did point out that a vote taken “at one minute to midnight” would be different from one taken when there were still months to sort things out.

The truth is that even the Dinner Party, though clever, fashionable and well-informed, does not know exactly how things are going to turn out. But its members all agree there has got to be maximum parliamentary scrutiny of the proposed deal on Brexit, and that Westminster should vote on it before the European Parliament does.

The Dinner Party has, in fact, become mad keen on parliamentary sovereignty, which it used to regard as a barbaric and outdated concept, of interest only to people like Enoch Powell and Nigel Farage, whom one took great care never to invite to dinner.