Tensions run high ahead of Syria vote
Some nights in Westminster you can feel a crackle in the air, you can sense the tension, and sometimes even see the weight of responsibilities that MPs know they carry collectively in the looks on their faces. This is one of them.
For government ministers this vote has been a very long time coming, an obvious extension of the action British forces are taking in Iraq.
Bombing is, to them, part of a complicated set of solutions, but a straightforward decision to make. Don't confuse that however with a sentiment that it is an easy choice.
MPs on all sides have agonised over making this decision and now, less than 24 hours before the vote there are still dozens who are yet to make up their minds.
The government is still confident of a comfortable majority. Significant numbers of Labour MPs are expected to vote with them, perhaps 50 or so have expressed as much. But on both sides of the argument tonight there have been last-ditch attempts to screw down supporters.
There are reports, denied by his office, that Jeremy Corbyn's supporters have been aggressively targeting Labour MPs to try to keep numbers backing action down. One MP who is pro air strikes reported a remarkable exchange with one of the leader's supporters who told him 'you want to start this? We'll finish it, so f*** you."
No question, this whole debate has become a proxy for control of the Labour Party, rather than a reasoned debate about the rights of wrongs of the action.
Also tonight though, in a private meeting with his own MPs, the prime minister abandoned his previous careful language, urging his side not to vote with Jeremy Corbyn and "terrorist sympathisers" - a remark that's been branded as offensive by members from other parties.
It's a mark of just how tense things are as the clock ticks down. Feelings are running so high, particularly in the Labour Party, that the way the debate has been conducted in these last few days will shape politics in the months to come.