Ms Swinson, who declined to be interviewed by Sky News alongside the other leaders, has said she would only support a compromise candidate for PM like Tory grandee Kenneth Clarke or Labour veteran Dame Margaret Beckett.The numbers in parliament make things very difficult. Anyone who is saying X will happen or Y is impossible is spinning. I'm looking at you here, Jo.
"He simply does not have the numbers," Ms Swinson said after the meeting.
"I have been crystal clear but I will do so again - Jeremy Corbyn is not going into Number 10 on the basis of Liberal Democrats' votes."
We can not tell and will not know until votes are actually cast. And possibly more than one round of increasingly fraught voting, as brinkmanship is exposed and people have to choose between what they do not like and what frankly terrifies them.
Here are the numbers in parliament:
Conservative Party - 288
Labour Party - 246
Scottish National Party - 35
Liberal Democrats - 18
Democratic Unionist Party - 10
The Independent Group for Change - 5
Plaid Cymru - 4
Green Party - 1
Independent - 35
(Sinn Fein have 7 MPs but they do not take their seats.)
Insanely, as it stands, no party can command a majority. This is why Johnson can't win a vote (currently at 0-7, probably the worst losing streak in government history.) Even coalitions are problematic, with 3-4 party combinations needed to get to the 'magic number' needed to command an outright majority.
(More on the 'Magic number' later.)
At the moment, parliament can't even vote to put itself out of its own misery, via a general election, because Johnson won't ask the EU for an election and the opposition parties won't trigger one without this guarantee.
The numbers don't make a GNU easy. Looking at a Corbyn lead option, first ...
A coalition of Labour , SNP, Lib Dems, Greens, PC and half of the independents gets to 322, which is the actual number needed to command a majority with the Speaker and SF not voting (though the Speaker would be obligated to vote with the government in the event of a tie.)
(That's assuming TIG4C do not support the GNU, even though they are meant to be fervent Remainers. Their hatred of Corbyn runs very, very deep.)
Excluding the Lib Dems and the independent MPs, Labour, the SNP, PC and Greens can get to 286, just behind the Conservative Party.
But the idea of a Corbyn lead GNU has proven problematic. The SNP and Greens have said they will support it. Assuming Plaid Cymru are also amenable, that gets the coalition to 286. But the Lib Dems and the Conservative rebels have said they won't support a Corbyn led GNU and want him to step aside for another 'less divisive' candidate.
The problem with that is any candidate that is 'less divisive' for the Lib Dems and Conservative rebels will be a very hard sell to Labour MPs. They are by no means 100% behind the party's declared policy of a second referendum, or even behind its previous position of a soft Brexit. There aren't too many Hard Brexit headbangers in Labour, but there are a couple; and there are a lot more Eurosceptics of various degrees of virulence (including, of course, Jeremy Corbyn) and others who will be thinking long and hard about where to position themselves, having looked at how their constituency voted in the referendum, and the mood of their local party.
Whereas the numbers for non-Corbyn lead coalition are more nebulous. Sure, you'll get the Lib Dems, the SNP and so on, and let's say you get TIG and ALL the independents. That gets you to 102.
How many Labour MPs are going to agree to put another Conservative MP into Downing Street? Particularly if the Conservatives and Lib Dems have refused to vote for Corbyn?
Even if the bulk of the party does - sullenly - vote for a Clarke (or whoever) lead GNU, Labour MPs who support leave probably won't. Based on the 'indicative votes' held earlier in the year, that's between 10 and 30 MPs who are opposed to soft Brexit or a second referendum. If it is 10, then the GNU works. If it is 30, it is tantalisingly close, but still short of a definite majority.
Again, it could work - Labour leavers might be persuaded to abstain, or more Tories might desert to support a non-Corbyn GNU. But it is all very sketchy, and anyone claiming one side or the other does or does not have the numbers is spinning. We won't know until votes are cast, possibly several rounds of them.
What is the 'magic number' needed to govern, anyway?
It is not 326, which is half the number of MPs in the house. You need to knock off SF's 7 MPs. That gets you 322. But even that isn't the number needed, because votes are passed on a majority of the MPs who are present to vote, not the absolute majority of all MPs.
Not one of the indicative votes involved more than 600 MPs voting. The far more critical Benn Act still saw 21 MPs mysteriously absent or abstain. You can get along with far fewer than 322, though it does make things trickier.
All of which gets us no further forward that we were at the beginning of this long and - I admit it, very unsexy - post.
Which begs many questions - will they (Libs and Cons) stick to their "Not Corbyn" position even if it means crashing out on the 31st? Will Corbyn? What is the 'magic number' anyway? Do Labour really need the Libs and Cons to get to it? Would enough Labour MPs support an alternative GNU for it to work?
The more I think about it, I am thinking that Corbyn should simply go for the VONC, defy the Lib Dems and Con Remainers to stop him, and see if he can run a short term government focused on getting a delay and a second referendum in spite of them.
It would be amusingly ironic if the Liberal Democrats - the party that have consistently opposed Brexit in all forms - managed to exclude themselves from stopping it. Which would destroy them with their voters in the subsequent election.