How Boris Johnson may win his Brexit vote, writes Robert Peston

The Saturday vote on Boris Johnson's deal will be closer than people think.

Around 18 or 19 of the Tory rebel exiles will vote for it, subject to a Letwin-ish amendment that the Benn Act applies until the whole of the Withdrawal Agreement Bill is law.

Boris Johnson will see that amendment as holding the feet to the flame of the Brexit Spartans.

• Boris Johnson 'very confident' MPs will back Brexit deal

He won’t hate it, whatever his public position. Because the ERG Spartans will fear if they vote against the deal and the WAB, that Brexit delay and no Brexit will follow.

Now, the DUP’s opposition to Johnson’s deal is a challenge for Johnson.

But as I said earlier on ITV News there is genuinely a chance Johnson’s deal passes - and I never ever said that about any of Theresa May’s Meaningful Votes.