The 1922 executive committee thinks it has finally laid a surefire trap for the PM Theresa May - by securing a promise from her to hold the second reading of the core Brexit legislation, the Withdrawal Agreement and Implementation Bill, before EU elections in two weeks.
The point is that either the bill passes, and she resigns as soon it becomes law (as she has promised to do), or it flops, which is what most Tories expect, and it becomes unambiguously clear that she can never deliver Brexit - in which case they will force her out in June or July.
Tory MPs assume she knows this. But they will drive the point home when the executive committee meets her next week (at her suggestion).
It would be tempting to say that her fate is in the hands of Jeremy Corbyn, her putative nemesis - in that if Labour agrees a Brexit pact with her, maybe that would see her Withdrawal Agreement Bill pass into law.
But a deal acceptable to Corbyn would alienate too many Tory MPs for the associated legislation to be approved. Which is why a very senior Tory told me she would be history before the recess at the end of July.
“It needs three weeks for the parliamentary process and then five to six weeks [for the members to decide] in the country."
Which means the coup would happen in the first week of June.
Robert Peston explains why Tory MPs think Theresa May will be replaced by the summer:
Peston is broadcast on ITV at 10.45pm on Wednesdays - but you can watch it live on this page at 8pm as the programme is recorded.