Amid all the tizzy surrounding the Euro vote tonight, one possibility hasn't gained much comment. It is that the amendment being proposed by Labour backbencher Ian Davidson will be called to the vote. This amendment calls for a referendum on both the Lisbon Treaty and on membership of the EU.
If it is called, the Nick Clegg can safely whip all Lib Dem MPs to vote for it as it is the only way that our favoured position of an in/out referendum can still proceed.
The Tories have indicated that they might withdraw their amendment to unify support around the Davidson amendment if that is called.
The fact that the Davidson amendment is allied to a Lisbon Treaty referendum makes it a bitter pill to swallow for those who don't want that, but it is a way out which avoids awkwardness of mass splits and resignations from the front bench.
Of course, if this is seen as a way out for the Lib Dem Leader, then look for either the Speaker to decide not to call Mr Davidson or for the Tories to press ahead with their amendment even so.