Nick Clegg has a strategy. You may not like it. It may not work. But it is not stupid. It could be called the Edward the Confessor strategy, after the king who, according to 1066 and All That, "was in the habit of confessing everything whether he had done it or not".

Thus he embraced David Cam- eron's "big offer" of a coalition and threw himself into making a reality of Liberal Democrat rhetoric about how marvellous it is for parties to work together. That meant taking responsibility for everything, whether it was his idea or not. He matched George Osborne's enthusiasm for deficit reduction, and then offered the body of St Vince of Cable as a modern Sebastian to take the arrows of outrage over the trebling of student fees. Clegg and Cable need not have offered their betrayal of a manifesto promise as a diversion from and a protection of their Conservative partners, but they chose to do so.

Clegg confessed to other crimes, whether or not a Lib Dem took primary ministerial responsibility for them, such as cancelling the schools building programme or abolishing educational maintenance allowance.

It was all part of the strategy. At a meeting at Chevening, the country house that Clegg shares with William Hague, the Foreign Secretary, at the start of this year, the three phases of the strategy were discussed. The five Liberal Democrat cabinet ministers, plus Norman Lamb, Clegg's adviser, and, interestingly, David Laws, agreed that the first phase, which they did not call the Edward the Confessor phase, was about unity. Until the spending review in November, they sought to establish credibility in balancing the Government's books. Even now, Clegg is sufficiently focused on this for one of his allies to tell me that one of the most important things about Thursday's electoral calamity was that the bond markets did not flinch – the price of government debt does not predict the early collapse of the coalition.

By the time of the Chevening meeting, however, the Lib Dems were in the middle of stage two, of limited differentiation leading up to the referendum on the alternative vote.

Now the plan is to move to stage three, of "negotiated, forewarned differentiation". The idea is that, having established that the parties can work together, it is safe for them to mark out their separate identities more. Clegg thinks it can be done only this way round. I am told that his view is: "It's easy to dial up differentiation; very hard to dial up unity and stability."

As I said, it is a strategy. There were two other main choices. One would have been not to have joined the coalition in the first place, but to have allowed Cameron to form a minority government and to have voted issue by issue in the House of Commons. But nobody argued for that. Only David Rendel, the former MP for Newbury and a member of the party's federal executive, voted against the coalition at the critical meeting a year ago – or, at least, when asked by his local newspaper if he would deny having voted against it, he said: "No". Even Charles Kennedy only abstained, along with an uncertain but very small number of other MPs.

Having decided for coalition, then, there were two ways to go – Edward the Confessor or Huhne the Snarler. This is where the real division among Lib Dems has been, although the leadership has been, until now, united behind Clegg's strategy. Chris Huhne's criticism of George Osborne at Cabinet last week was newsworthy precisely because it marked a break from nearly a year of coalition ministers being nicer to each other than their single-party predecessors.

Party members and backbench MPs might have preferred to see a different kind of coalition, one that was less mutually respectful, and specifically one that did not take responsibility for the tuition fees decision. That was where Clegg and Cable made their big choice. Looking back, they made a mistake, although it is not clear whether the error was to put a Liberal Democrat in charge of breaking the party's promise, or whether it was Cable's honesty in admitting that he had broken it. The policy he came up with was so similar to a graduate tax that he could have pretended it was a graduate tax. No one would have believed him and young Pink Floyd and his friends would still have swung on the Cenotaph and broken windows at Tory HQ, but the index of betrayal would have been lower.

Even better, from some Lib Dems' point of view, would have been to let a Conservative devise the policy and then abstain in the vote, as the coalition agreement allowed. The Bill would have gone through, without quite so many supposedly "progressive" complications, and the Lib Dems would have been castigated for failing to oppose it, but the index of betrayal would have been lower still.

Instead, there is a certain courage in Clegg's chosen course. He is neither a fool nor a victim of events, although at the time of the coalition negotiations he was certainly operating in a confined space. He tried to make the best of his party's big moment, the hung parliament about which all his predecessors back to Lloyd George used to dream.

Those Lib Dems who would prefer a more arm's-length coalition are, he would say, simply shirking their responsibility to make coalition government work. Actually, I suspect that they have a better idea of what might retain more Lib Dem votes at the next general election. It is unfortunate that democratic success seems to require a certain shirking of responsibility – as was demonstrated last week by the triumph of Alex Salmond, a politician who has built his career on blaming the great external enemy.

And the trouble with Edward the Confessor, says 1066 and All That, is that because he was "with difficulty prevented from confessing to all these and many other crimes committed in his reign", he was "thus a Weak King".

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