To set up a new Coalition with a party that has about half the seats the other two have in the driving seat would be, regardless of what the PR-loons shout, dangerously undemocratic, unworkable and, potentially, not constitutionally legal.
Well, if you think that the party with the most votes leading the government is undemocratic, then, err, perhaps we are using different definitions of the word democratic?
I also disagree on the constitutional point: The constitution is blind to party (except perhaps in the existence of the Whips office...) The PM can be any MP (or anybody else, I suppose) who has the confidence of the Commons and can hence deliver Supply. So if Caroline Lucas was called to the palace, but had the support of a Labour and Conservatives on a Supply-and-Confidence basis, she could accept the position of PM entirely constitutionally. I wouldnt claim this is a likely scenario, nor one which is likely to survive except with the support those Environmentalist!Space Bats and their mind control rays, but it would at least be constitutional!
I agree with your point about it being entirely and utterly unworkable in any practical sense, though!
But no - the ASB-ish nature of the Lib Dems topping the national poll (in any circumstances, their party machine isn't strong enough locally, and this isn't America) aside, this has remained plausible and I assume the Coalition arrangements will remain so. Labour will get first dibs but I can see the above Tory proposal coming true - particularly as Stodge suggested that a Mili-D led Lab-Lib government isn't on the cards.
I agree: I know that a couple of opinion polls were showing these sorts of numbers in that week after the first debate, but translating outlier opinion polls in to GE results seems to require, if not ASBs, at least a certain number of high-atmosphere chiroptera of indeterminate origin. Of course, this is really the POD of the timeline, so I think we can let it go!
Clegg really would be in a bind here. Sure, he has choices, and could support either party in coalition, or even just supply-and-confidence, but unlike OTL he wont have the excuse of "the only way to secure stable government", and which ever way he chooses he will piss off a portion of the party and his voters. Or be seen as week and indecisive if the negotiations last too long.
I cant see any way for Gordon to hang on for long, even if, as leader of the largest party and incumbent PM, he has every right to do so. Surely Clegg would demand he goes as perquisite to any serious negotiation (as per OTL)? I think that Milliband (D) would be the most likely candidate for coronation, but also agree that there is very little chance of one happening, as why would anyone give the Tories a "Two unelected PMs (or party leaders)" stick for free?
Im not sure what Camerons actions would be at this point: In OTL he held a strong negotiating position as the leader of the largest party and only practical leader of government (either in coalition or as part of a s-and-c deal), and was able to come out and give his speech and offer to the Lib Dems with the knowledge that he could bring his party with him. In TTL, he hasnt really won many (any?) more seats, he will have major figures in the Party (Ashcroft!) furious about how the debate went and its consequences, and would have to start a bidding war with labour even to get the Lib Dems to start talking...
If GBs resignation is the minimum offer from Labour, what would the Tories have to give? Referendum on AV, as an opening gambit, but STV or even things like renewal of Trident might be on the table. With hindsight, a guarantee on Tuition Fees would seem automatic, but it might not have been so obvious at the time...
Of course, The situation in Greece is likely to flare up over the weekend, so there will be significant and increasing pressure to form a Government quickly.
Hear, hear. Super stuff!