There are no good options left for Theresa May. Barring a remarkable turnaround (and there is more optimism on the government side than there was this morning), she is not going to get enough on the backstop to satisfy the DUP and so her deal will not pass on Tuesday. Her deal failing will trigger a series of events that will involve the Commons not only compelling the government to request an Article 50 extension but also seeking to take over the Brexit process.
Over the weekend, the views of key Tories on how disastrous this would be have hardened up. One influential, loyalist backbencher told me earlier that it would be better to pull stumps and fight a general election than let Letwin’s expected amendment, which would compel the government to hold indicative votes and then to try and negotiate whatever MPs back, pass.
If one was being deeply cynical, the question for May might be: would you rather your government was brought down in a confidence vote by ERG-types or Nick Boles and co? If May would prefer the latter, then the route to that is to pass a conditional vote, and then pull the votes on no deal and an extension on the grounds that the House has backed a position and she now needs time to negotiate it. This would almost certainly result in a confidence vote, and one that May might well lose.
If no alternative government could be formed in a fortnight, there would then be a general election. May, presumably, would campaign on the basis that she needed the public’s backing to deliver Brexit. But this strategy is not without risks. Lots of Tories would want May replaced before another election, but it is not clear what the mechanism for that would be. Then, again, the best that May can hope for now is to find the least worst option.