Tory Rwanda rebels have shown their hand.
They have been able to demonstrate their side is willing to go further than before Christmas - and that they have the numbers to defeat the government tomorrow.
Two prominent figures on the right - salaried deputy chairmen of the Conservative Party - have resigned their posts to show the strength of feeling about the Rwanda issue.
Meanwhile, 70 Tories, ex-Tories and DUP MPs have turned out to vote for an amendment to block international law from applying to the Rwanda policy in defiance of the PM, even more than signed the amendment.
The question now is whether the government is prepared to risk a defeat by going ahead tomorrow, or whether ministers abandon a plan to hold a vote in fear of defeat.
Some 60 Tory MPs, including 10 former cabinet ministers, voted against the government.
If 33 of these are prepared to hold their nerve in 24 hours and vote against the government in the next vote on the bill, then the bill falls and suddenly the Sunak government is facing an existential crisis.
For Rishi Sunak to lose this bill - which he has ended up making central to his premiership - is not automatically fatal.
It is not formally an issue of confidence.
But it may not be far off.
The biggest question in politics therefore is whether the chief whip and the PM hold tomorrow's third reading of the bill, or pull it.
There are people in surprising parts of the Conservative Party who believe that Mr Sunak's premiership is in dire straits and that a change of leader - however mad that might seem to the country - could be necessary.
They're not currently for changing their leader, but they're not viscerally hostile.
All of this today means red lights on the dashboard should be flashing in Number 10.