Peter Mandelson once texted Danny Alexander when they were sitting across the table from each other in a meeting – a small example of how mobile phones have changed the interpersonal dynamics of politics as well as those of family holidays. Mandelson's text asked if Andrew Stunell, Alexander's Liberal Democrat colleague, "might be a bit more civil so we could make progress". Alexander nodded and showed the message to Stunell, sitting next to him.
This was in the third and last meeting between Labour and Lib Dem negotiators on the Tuesday after the general election three years ago. Mandelson's texting tactics are recounted by Andrew Adonis, who was also on Labour's negotiating team, in his Five Days in May, published at the start of the summer. All Adonis's books are important, and now is a good time to read this one. The Labour Party rule book should be changed so that, instead of requiring candidates for elected public office to be members of a trade union, they should be required to have read his Education, Education, Education in defence of academies, and this book, on how not to negotiate a coalition. He wrote most of it at the time, as a record from the Labour side of the five days between the election and the Cameron-Clegg coalition taking office, but couldn't publish it straight away because he took a non-partisan job after leaving government.
Now he is back in the fray as a shadow minister in the Lords, but the delay means that we get the benefit of his wisdom after three years of coalition, and in good time for the next election.
Adonis's main argument is that a coalition between Labour and the Lib Dems was possible. The things Labour people don't like about the past three years could have been avoided, he argues, because the Democratic Unionist Party and Scottish Nationalists would not have voted down such a coalition. It would have been uncomfortable to have to rely on Peter Robinson and Alex Salmond, the DUP and SNP leaders, but it is probable that a Lib-Lab coalition could have had a small majority in practice, most of the time. The DUP is hostile to the Tories, and Salmond could not have afforded to let Cameron in.
Adonis's strongest argument is that 54 per cent of voters had voted for Labour and the Lib Dems and for the Alistair Darling deficit-reduction plan they both supported; against the 37 per cent who voted for the Tories and George Osborne's deeper cuts.
Adonis blames Clegg, whom he regards as a crypto-Tory on everything except Europe, a cause Clegg betrayed in any case, and – although he is too polite to say so directly – he also blames Brown. The only way Adonis's plan might have worked would have been if Brown had announced his resignation as Labour leader the day after the election. This would have held out the prospect of a Labour-led coalition with Alan Johnson or David Miliband as prime minister, and it would have countered the momentum of Cameron's "big, open and comprehensive offer" of a coalition to the Lib Dems.
Brown, however, thought that he had to stay on to push a coalition deal through a reluctant Labour Party. Even when, on Monday, he belatedly announced his intention to stand down, he was still thinking of staying on until at least the autumn, to oversee an early referendum on the voting system. No one in the Labour boss class had the insight and confidence to advise him to pack it in. In particular, neither Johnson nor Miliband said: "This is mine."
It would have looked odd, as I remember from the time, for a prime minister to emerge who had not taken part in the televised election debates – another good argument against such debates, and in favour of reminding people that we have a parliamentary not a presidential democracy. But "looking odd" is hardly a conclusive argument of democratic principle. If Labour had been better prepared, and if someone around Brown had showed a bit of steel, it is possible that perceptions could have been changed. Possible, but unlikely.
I think Clegg had decided straight away the arithmetic was against a deal with Labour. But that doesn't excuse Labour's lethargy in reaching for the impossible. Brown and Adonis were the only two who took a Lib-Lab coalition seriously, but Brown was the main obstacle to it, while Adonis was an unelected peer – although Ed Miliband did have a Fotherington-Thomas moment on the Saturday when he said, "I hate to say it, but I think this is destined to succeed."
The bookies say there is a 50 per cent chance of another hung parliament, so here are three lessons for next time. The first is that parties have to be ready to change leader at short notice. Look out Clegg; stand by Vince Cable, or anyone better able to deal with Labour. The second is that Ed Balls shouldn't be allowed near the negotiations. He tried to win arguments last time, with Chris Huhne on economics and with David Laws on the children's database, which did nothing to make coalition easier. And the third is: go for the impossible. To do anything less is to let the voters down.