Well, that didn’t last long. The new era of coalition politics, ushered in five years ago, is about to expire. Or, at least, it will if the polls are correct – and Cameron and Clegg don’t have enough MPs between them to carry on with the existing arrangement. Even if they do (possibly with support from UKIP and the DUP) we can’t just assume that the Lib Dems will play ball.

If the current coalition falls, it almost certainly won’t be a different coalition that replaces it. The only other combination not ruled-out by the parties concerned – a Labour / Lib Dem coalition – is unlikely to have the necessary numbers.

So, what we’re looking at is a minority government composed of ministers from a single party. Given the SNP’s prior commitment to “locking out the Tories”, this means a Labour minority government.

However, as Phillip Cowley explains in the Spectator that is very far from being the end of the matter:

“…there is a real difference between getting into government and then governing. Calling the SNP’s bluff only helps with the first of these. After that, on vote after vote, deals will have to be done, or the government will achieve nothing.”

The distinction between being in office and being in power is sometimes over drawn. For instance, only the government can propose measures to raise taxation and spend money (though opposition parties can vote these down). There are also many executive powers that be used without the say-so of the legislature.

Nevertheless, it’s a pretty weak sort of government that can’t rely on getting new legislation through the Commons – and which doesn’t even control the ‘business’ of the House:

“A lack of a government majority would also mean no government majority in the Commons’ various committees – both select committees and public bill committees. Most importantly of all there would be no government majority on the various programme motions that timetable legislation…

“…On bill after bill, the opposition parties could combine to bog the government down, dragging out legislation for months, keeping MPs up all night in the sort of all-night sittings that had (thankfully) become a thing of the past… trying to govern like this would be hellishly difficult.”

Leader of the House is about to become the toughest job in politics (with Chief Whip a close runner-up).

Last week, Ed Miliband made a rather bold promise: “I am not going to have a Labour government if it means deals or coalitions with the Scottish National Party.” If he becomes Prime Minister, then he’s going to spend the next five years (assuming he lasts that long), explaining what he did and didn’t mean by that statement. As Phillip Cowley puts it: “there may be no Deal, then, but there will have to be deals.”

Crucially, not all of these deals will be Labour-SNP deals – because Labour plus SNP isn’t the only way of building a majority. Indeed, on a vote-by-vote basis, one can easily envisage a situation in which three different two-party majorities are possible: Labour plus SNP, Labour plus Conservative and Conservative plus SNP.

The issues on which each of these combinations might come together are as follows:

Labour plus SNP – putting Miliband into Downing Street; locking out the Tories; blocking the in/out referendum; unwinding Coalition reforms on welfare, education and anything else the Unions demand.

Labour plus Conservative – financial measures required to eliminate the deficit (albeit at a glacial pace); retaining Britain’s nuclear deterrent; blocking any move towards a second independence referendum.

Conservative plus SNP – a possible grand bargain involving further devolution to Scotland in return for radical decentralisation of power within England; anything to make Ed Miliband’s life difficult, as long as it doesn’t bring down his government (SNP condition) or undermine UK finances or defences (Conservative condition).

This three-majority scheme, though complicated enough, is itself a simplification. For a start, the Lib Dems may still have enough seats to throw the occasional spanner in the works. It’s also possible that the SNP and/or the Conservatives will threaten to withdraw co-operation with Labour on common-ground issues if the government doesn’t give way on certain other issues.

A final possibility is that enough voters will see sense on Thursday and return the current government to power. The Coalition is an unlovely arrangement, but given the alternatives we’ll be sorry to see it go.