David Maddox: How did coalition last five years?

Prime Minister David Cameron and Deputy Prime Minister Nick Clegg. Picture: PA

In the middle of a question and answer session at the Liberal Democrat spring conference in Liverpool, the Lib Dem leader said that the Quad – himself, the Prime Minister, Chancellor and Chief Treasury Secretary Danny Alexander – had had their last meeting to sign off the Budget and that was the end of their ministerial business before the election.

The coalition will not officially be dissolved until after the election when the Queen invites either David Cameron or Ed Miliband to be the next Prime Minister and, on the 5/1 shot that the Conservatives and Lib Dems strike another deal, then in effect it won’t come to an end at all.

But the remarkable thing for many people is that the distinctly unhappy marriage lasted beyond the end of 2010 and has gone the full distance.

According to senior Lib Dem insiders, people perhaps should not be surprised.

The main glue in the deal was the coalition’s principal mission, which was to heal the economy and provide political and economic stability. This it has largely done and the desire to hold to the plan (despite Vince Cable’s odd protestations) has largely kept both sides focused.

But also important were the relationships formed and the surprising degree of mutual trust.

One of the key relationships was early on in the whips’ office – the enforcers and party managers – where the Tory chief whip in 2010 Patrick McLoughlin and Lib Dem deputy chief whip now Scottish Secretary Alistair Carmichael struck up a friendship and a successful working partnership.

According to sources it was this relationship which may have saved the coalition at the only moment when it genuinely may have fallen. The crisis was over David Cameron using the veto in Brussel in 2011, which incensed Mr Clegg who was not even consulted.

A DUP debate later in the week on the EU had seen a form of words agreed to get both Tories and Lib Dems to support it while pro-EU Lib Dems could go home early. But then it is understood Mr Clegg said he would vote against.

A whips’ operation got the Tories to bring in all their MPs quietly without Labour scenting an unlikely Commons defeat for the government while the Lib Dems were told they could abstain. It worked and may have saved the coalition from tearing itself apart.

If they are to work together again though, the issue of the EU may prove a much bigger stumbling block in the next parliament with Tories and Lib Dems divided over a referendum.