LAST night the parties were still locked in negotiations over who will be allowed to form the next government.
The task is to reach the magic number of 321 MPs, giving a clear majority in the House of Commons.
Nick Clegg made a Lib Dem-Tory coalition the most likely outcome after saying the party with the most votes should have the first chance to form a government.
However, this option is far from problem free. Core Lib Dem voters are uncomfortable about the idea of entering a pact with the Tories, with whom they are ideologically opposed on key issues.
Factions within the Tories will also resist the concessions the Lib Dems will demand in exchange for a partnership, including the radical electoral reform Clegg craves.
The prospect of a rainbow coalition between the so-called “progressive” parties is still an option if talks between the Lib Dems and Tories break down.
Brown would have to conduct a grand balancing act during his final days in power, bringing together almost every left-leaning MP in the UK. The coalition would include Labour, the Lib Dems, Plaid Cymru, the SDLP, the Greens and Alliance. If all of these parties agreed to come together it would scrape the 321 seats with nothing to spare. Labour could also try to bring the six SNP MPs on board to give a little elbow room.
In theory the parties are a more natural fit than the Lib Dems and the Tories and Labour claims the split of votes shows the electorate is in favour of a centre-left government.
However, the coalition would face accusations of propping up a zombie government with an unelected leader and muscling out the popular choice for Prime Minister.
Ironically, a further problem was actually created by Brown’s resignation yesterday: the leader of the coalition would not have appeared on the live televised debates.
While Labour would argue the UK does not operate a US-style Presidential system, placing far less importance on the party leaders, the influence of the debates has been undeniably profound.
The final option is for Cameron to limp along with a minority government. If no deal has been struck before the Queen’s speech on 25 May she could, through her cabinet secretary, ask the most viable alternative – in this case Cameron – to form a government.
Cameron would seek to call a snap election as soon as he was able to convince voters he deserved the chance to form a majority government.
But as the exhausting battle for Number 10 becomes increasingly desperate, a second election is looking increasingly likely whoever gets the keys.