Months ago the extraordinary EU leaders’ summit to ‘seal the deal’ on Brexit was conceived as a big momentum moment; a heavyweight, set-piece occasion in which Theresa May’s Brexit deal took on an unstoppable quality.

The summit atmosphere was never intended to be to be chummy, but still, this was the moment when the cover-up was applied to the negotiation room bruises and all 28 leaders agreed that these were the only viable terms for the United Kingdom to make an orderly exit from the EU.

If the Chancellor of Germany and the President of France both backed the deal for the sake of stability on both sides of the Channel, would a rump of Brexiteers really look credible when defying them?

And yet in Brussels this week it is clear to many insiders that this ‘moment’ has passed even before it has dawned.

With 91 MPs understood to be in open opposition to the deal in London, the handshakes that take place on Sunday afternoon between Mrs May and the 27 the EU leaders will be accompanied by hollow, pitying smiles.

“It has already taken on the air of a wake, not a celebration,” said one senior EU official involved in planning the summit. “Everyone knows it looks next to impossible for May to sell this deal, even though it is the only one she’ll get.”