Let us hope that we in the Liberal Democrats can, unlike the Labour party, analyse the causes of our disaster without rancour. The first thing that needs to be said is that history will be kinder to Nick Clegg than the electorate has been. Back in May 2010, many politicians and pundits predicted confidently that the coalition would not last. The fact that it did, for five years, was largely due to Clegg’s dedication and skill. His typically eloquent resignation speech spelt out legitimate achievements of which he can be proud. His Question Time appearance was superior to those of both Cameron and Miliband, and the election campaign he led was also, under Paddy Ashdown’s chairmanship, the most professional of the 14 in which I have participated. So why did it not work? I would argue that it was doomed even before the election began for six reasons.

1 Long before the 2010 election Clegg announced that in the event of a hung parliament he would talk first to whichever party held the largest number of seats and he repeated that this time. I clearly recall wincing when on television he described the constitutional practice of giving the incumbent the first go at forming a government as “fuddy duddy”.

Who on earth advised him on this heresy? It is significant that in the closing days of this election campaign a number of independent constitutional authorities such as Vernon Bogdanor were reminding us of how the convention worked in our political history and also debunking the “illegitimacy” argument being advanced against a possible minority Labour government.

I still kick myself for not querying Clegg at the time, and I venture two excuses. I never interfered with any of my successors: former leaders should be seen and not heard. And unlike Ashdown, Charles Kennedy and Menzies Campbell, all of whom were colleagues and friends, I really did not know Clegg and indeed recall having met him only once. Not very substantial excuses, I admit. So I take my share of blame.

Facebook Twitter Pinterest Nick Clegg’s ‘eloquent’ resignation speech - video

The importance of this error is that after the 2010 election he did not go to meet Gordon Brown first. Had he done so, instead of leaving talks with Labour to his acolytes later, he could have explored seriously the possibility of a Lib-Lab coalition, one more in tune with what the voters had understood of our consistent Liberal ideology under all six leaders since Jo Grimond. The arithmetic might still have prevented it, but he would have secured two things: an earlier timing of Brown’s dignified statement standing down to make way for a new Labour leader and, more crucially, far better terms from the Tories.

2 With all his knowledge and experience of European politics Clegg should also have been more aware of the folly of rushing to government formation. He should have said: “We don’t want to be like Belgium, but the press should calm down and recognise that the Queen’s government goes on normally while we take the necessary days to consider how best to form the programme for a new government.”

Nick Clegg – the inoffensive ordinary guy who could have been great Read more

3 As party leader, Clegg puzzled us all by ignoring the more senior members of his Commons team including Campbell, Alan Beith, Malcolm Bruce, Simon Hughes and Kennedy. Instead he created a negotiating team entirely of newer and younger colleagues whom he could dominate. He himself had become leader after only two years in parliament and had been leader for less than three. He compounded this omission by not appointing any of the senior members subsequently to his ministerial team.

Perhaps there is some odd flaw in his judgment of people – he had also been rather ungracious to those who had opposed his original selection as MEP in the east Midlands, such as the Chesterfield MP Paul Holmes whom he had sacked as housing spokesman. Whatever the reason, I believe it contributed to poor collective judgments.

4 The most obvious reason, for which he later made fulsome apologies, was the about-turn on student fees, after which, as Anne Perkins wrote in this paper on Saturday, it was “almost impossible to get across the achievements that Lib Dems could reasonably be proud of”. I would delete the “almost”. I remember some time later getting dark looks at a party meeting when I said that “a laundry list of alleged achievements in the coalition will not wash”. And so it proved.

There were other misjudgments: the hasty AV referendum was one

The reason this volte face was catastrophic was nothing to do with student fees. That this was widely misunderstood was clear from the “lines to take” issued to us all from party HQ. We were urged to ask forgiveness for one thing we had got wrong against so many other things we had done well. That missed the point – at a stroke, we had lost trust as a party, one of the few tangible assets we had especially after the Kennedy/Campbell decision to oppose the invasion of Iraq. The pledge was not just in our manifesto – every candidate, including Clegg, had campaigned on the issue.

You cannot publicly promise something in an election and then do the opposite and get away with it. So how did it come to be dumped? One explanation I have heard is that Clegg never thought the policy was correct but felt saddled with it by party conference. If true, I have considerable sympathy because in my day I had the leader’s veto over anything in the manifesto. That useful but undemocratic provision was swept away in the party’s new constitution. But it is not an adequate excuse for the disaster that engulfed us. It became obvious to those of us campaigning for the Scottish parliament elections the following May that we were beginning to suffer serious losses as a result.

Paddy Ashdown: opinion polls killed Liberal Democrats' election chances Read more

5 But there were other misjudgments. The hasty AV referendum was one. The public regarded it as a strange priority and tedious waste of time and money, motivated purely by party interest; and it did not even have the merit of being party policy. It should have been delayed until a proper policy had been agreed – at least the resurrection of previous recommendations for single transferrable vote in urban constituencies and AV in rural areas.

Our attempt to improve the NHS re-organisation bill left us not getting any credit but being identified with that unpopular measure.

The House of Lords reform bill meanwhile ignored the party’s true history on the matter and was always destined to fail as it did in the Commons. Even in the latest manifesto, a constitutional convention was given only passing mention – when we desperately need a proper examination of how a reduced size senate could be elected by the component institutions of the UK (including the House of Commons) and thus provide a quasi-federal chamber able to tie in with home rule for the nations and an English Grand Committee for the Commons.

6 Holding a television debate with Nigel Farage on Europe was an ill-thought-out wheeze. Who advised on that? Never mind that most viewers judged wrongly that Farage’s bluster had won against Clegg’s reasoned arguments – it took the Ukip leader out of maverick irrelevance and gave him his first exposure as a serious leader. Following that, the Lib Dem leader was perceived as being just one among the other minor party leaders.

The Lib Dem demise in perspective – where Nick Clegg really went wrong | Letters from Liberal Democrat lord Trevor Smith and others Read more

Others will contribute to thoughtful post-election examination. We need to recharge our batteries and restate our values. I have been misinterpreted as saying it will take decades to recover. What I actually said was that this election has set us back decades. I was referring to the election of 1970 when I sat in the Commons as one of a party reduced to six MPs. Yet we soon regained momentum and began a remarkable recovery. We must do so again. The party has sufficient resilience and determination. Indeed, the thousands signing up to membership in recent days suggest that my optimism is not misplaced.