The surprise is not how badly the two parties within the Coalition are getting on, but how well. The durability is at least as marked as the inevitable fragility. Yet, increasingly, I sense that this coming together of two parties at a national level will be a freakish one-off rather than the start of a pattern even if, as is likely, the next election produces another hung parliament.

On Radio 4’s Week in Westminster, I interviewed the former Defence Minister, Nick Harvey, one of the Liberal Democrats who lost his job in the reshuffle. Admittedly, he is bruised, and openly admits to being disappointed at what happened to him. Yet what he says is illuminating irrespective of his unsought freedom to speak more candidly. Harvey suggested that the Liberal Democrats would think very carefully before entering another national coalition.

In making his case, he spoke of a conference that took place several months after the formation of the Coalition with their counterparts in coalitions across Europe. According to Harvey, one message from their European equivalents came through loud and clear. For coalitions to work, virtually every policy has to be agreed for a full term during the post-election negotiations. Equally important, every policy area where there can be no agreement must be firmly established and clearly thought through. The scale of such negotiations explains why in some countries coalitions are not formed until several months after an election. Harvey told me that he and his colleagues realised regretfully at the end of the conference that they had accepted too much too quickly and it was too late to reconsider. The gathering took place as the row over the tripling of university tuition fees was erupting.

Now on the backbenches, Harvey suggested quite reasonably that Liberal Democrats should take their time if there are more hung parliaments and that this was a view widely shared in his party.

But UK politics does not allow for time. Five days was pushing it after the last election as the two sides negotiated conditions. The impatient, restless culture demands a Cabinet in place almost immediately. Any pause is seen as a sign of weakness and generates panic. Yet time is what is needed in such circumstances.

If an exhausted, sleepless Nick Clegg had no need to rush, he might not have given some ministers on the right wing of the Conservative party so much early space to make their moves. He would have demanded more for the Lib Dems, or at least been more emphatic about what they would not accept. No leader of a third party will get such time to recover from an election campaign and to contemplate at length an unavoidably daunting and highly charged game of power politics. In the two hung parliaments since the war, in February 1974 and in 2010, a government was in place by the Monday evening in the first case and Tuesday in the second.

Yet imagine the political storms brewing if there is another hung parliament. Would David Cameron be safe as a leader who had failed to secure an overall majority again? After the traumas of the past few years, could the Liberal Democrats even contemplate another Con/Lib coalition? But could they really switch to a Lib/Lab coalition, rushing into an administration that would partly seek to reverse some of what had been implemented by the Con/Lib government?

There are other reasons why national coalitions for the UK are rare. Although the next election might well be close, the defeat of the referendum on electoral reform means we retain a voting system that usually leads to one party winning an overall majority. That is one of the reasons the two bigger parties are broad coalitions in themselves. As Polly Toynbee and David Walker show in their illuminating new book, Dogma and Disarray, with their forensic focus on policy rather than the red herring of personalities, the current Government has followed an agenda rooted in the radical right.

Yet David Cameron leads a party with a substantial and noisy number to the right of him. In the Labour Party, there are ultra-Blairites close in policy terms to Cameron and the Orange Book Liberal Democrats, while Ed Miliband still has voices to the left of him even though he is to the left of those that still regard Tony Blair as their hero. In those countries where coalitions are the norm, parties tend to be more narrowly defined. Here when a single party is elected to power, it is already a coalition.

There are plenty of examples where coalition works in local government, a reason why Liberal Democrat activists have shown such remarkable tolerance of a national partnership that threatens to destroy their important local base. But England is a centralised country. It is much easier for parties to agree in a local council with puny powers compared with national government where values and ideology are tested on a daily basis. Not surprisingly, in the latest Social Attitudes Survey, those favouring coalition as a form of government has dropped to 28 per cent in contrast to the optimism of May 2010.

The finding adds to current multi-layered calculations. Liberal Democrats do not have to stay put in order to prove that coalitions “work”. Even some Liberal Democrats conclude that at a national level they do not, at least until the many lessons of this current experiment are learnt.

s.richards@independent.co.uk

Twitter:@steverichards14