Boris Johnson has written his column again: saying that Brexit is a great opportunity but that Theresa May’s Chequers proposals are a disaster. The peg this week is the condition of Greece.

The reason why it matters is that every time Johnson goes over this ground, it becomes harder to see how he could plausibly vote for May’s final deal, which will essentially be Chequers plus a series of further concessions.

At the risk of being a stuck record, there’s no need to worry over much about the detail of Chequers: what matters is that May has chosen between the two Brexit destinations of low regulatory freedom, high access to European markets (Norway) and low access, high freedom (Canada): she wants high access, low freedom.

Labour will vote against May’s deal regardless of its content – the joy of Labour’s six tests, from an opposition perspective, is that the government can only fail them. So will the SNP, the Liberal Democrats, Plaid Cymru and Caroline Lucas, the sole Green MP. So the government only needs to lose seven MPs over the side to be in serious danger of defeat.

I think it is highly unlikely that any of Labour’s pro-Leave MPs will break the whip to vote for May’s deal as if it isn’t good enough for Boris Johnson, it isn’t going to be good enough for Frank Field or Kate Hoey either. But May’s proposals aren’t going to guarantee a high enough level of access for it to be worth the political price that Labour’s pro-Europeans would have to pay to vote for it either.

So the question is: how close to the danger zone of losing more than seven of her MPs is May? Johnson is obviously one, Jacob Rees-Mogg another, Andrea Jenkyns is a third, Steve Baker a fourth, Bernard Jenkin a fifth, Simon Clarke a sixth, and Conor Burns, Johnson’s loyal bag-carrier, a seventh. And that wasn’t a difficult exercise: I haven’t included anyone who has quit who is in a heavily Leave area, and there are a number of big name Eurosceptics I have left out, such as John Redwood. There are plenty more near-certain rebels out there.