Theresa May faces down Nicola Sturgeon and Tory rebels
It is a properly interesting day in the dysfunctional world of our great British democracy.
Firstly, we have Nicola Sturgeon demanding a second referendum on Scottish independence, to be held between the autumn of next year and the spring of 2019 - with her justification that Theresa May has ridden roughshod over her conviction that Scottish people want to remain members of the EU's single market.
Secondly, we have Tory Remainer MPs, led by ex-minister Nicky Morgan, putting pressure on May and her Brexit secretary David Davis through the Tory chief whip to provide new words on a so-called "meaningful" final vote for Parliament in two years: not just a promise of a vote on any deal negotiated by the PM but - more importantly - also a vote if there is no deal and we tumble out of the EU.
As we speak my sense is that Davis and May are minded to refuse to give this commitment.
But that would come at the risk of an embarrassingly significant rebellion by the more passionate Remainer MPs and even a possible defeat for the government in the Commons vote.
On the Scottish referendum, May will indicate nothing definitive today.
Her preference is for there to be no second plebiscite - obvs.
But if that line can't he held, she'll certainly refuse a vote till after the 2020 general election - because to concede a Scottish independence vote at a time when EU departure negotiations will be at an all-consuming critical juncture, and also when hospitals and schools are very likely to be in need of urgent remedial help, would be in effect a political suicide pact.
That said, I am a bit surprised by Sturgeon's decision to nail her colours to an early referendum, because:
It seems odd to have a vote before Scots know the shape of the UK's deal (or no deal) with the EU.
If it actually came to a vote, May is in a position to argue that Scoxit - Scottish departure from the UK - would be even more economically catastrophic than her predecessor Cameron claimed it was in 2014, because there are greater uncertainties today than there were then about what currency Scotland would be using.
The point is that May would find it hard to give a commitment that Scotland could continue to remain in a sterling zone and have its monetary affairs controlled by the Bank of England sine die, because that would bring risks for taxpayers in England, Wales and Northern Ireland that they would think unfair.
And it would take many years for Scotland to join the EU and - if it so desired - the Eurozone.
So a small Scottish economy might find itself having either to keep the pound, but have no influence over interest rates and monetary conditions, or invent a currency of its own - which would bring the serious risk of big losses for Scottish savers (because in its early years, a new currency would almost inevitably be a weak currency).
Gosh: politics will remain fractious and interesting for some while yet.