Two and a half years on, neither man can ignore this awkward reality any longer. In coalitions made up of two parties, things happen in twos. When times are good both leaders benefit, but when they are bad there is double the trouble.
After a summer in which politics was largely forgotten in a bubble of Olympic ecstasy, it is back with a vengeance and in a form more visceral and irrational than ever. Cameron and Clegg are suddenly, from almost nowhere, in the firing line; their ability to remain as leaders of their own parties and the country in question.
MPs and activists in both governing parties are restless and some are thinking dark thoughts. Last week in the House of Commons a young Conservative backbencher, who until now would have been listed in the "thoroughly loyal" column on the Tory whips' office blackboard, was asked about talk of Boris Johnson being installed again as an MP so that, at the right moment, he could mount a coup and replace Cameron as leader and prime minister. "There are lots of MPs who would fall on their swords to allow Boris in," said the MP. "Things are that bad. Lots of people don't know whether they want to be here any more. People are very fed up." Another member of the 2010 intake – now packed with individuals who, following the reshuffle, fear they will never enter government – said merely: "For me, it is anyone but Cameron."
It is true that for every Tory MP who plays up the threat to the prime minister's leadership from Johnson or A N Other Tory there are several who will dismiss the idea out of hand. "It is for the birds," said one normally vociferous critic of the prime minister. "Look how well he did on the Hillsborough announcement. I had people coming up to me from the Labour side saying how brilliant he was, and it is true. He was. It is all bonkers." In Clegg's case, his MPs are more solidly supportive, though they are not uniformly so. In many respects the discipline of the Liberal Democrats is remarkable, given their position in the polls and the Tory blows they have taken over electoral reform, House of Lords reform, and now the apparent systematic throwing overboard of green policies by No 10 and the Treasury. But there are some notable Lib Dems – and not just Lord Oakeshott – who believe Clegg is now so toxic that the party will be wiped out unless it installs Vince Cable in his place well before the next election.
Before what is bound to be a gossip-fuelled party conference season in which Lib Dem flirtation with Labour (and vice versa) will be added to the mix of plotting, irresistible visions of the future home into view. Could dishevelled Boris, with his wild and abundant blond hair, and bald Vince come together in the Rose Garden to renew the coalition? What exciting deals could be struck? Would Cable – an opponent of Heathrow expansion – back a Boris Island airport in the Thames estuary in return, perhaps, for Johnson supporting a new push on the environment, maybe with Boris bikes extended nationwide? Or, after the next election, will it be Vince and Ed (Miliband) in the "progressive coalition" so longed for by many on the centre left?
As yet, the Tory insurgency against Cameron is small and incoherent. Around a dozen MPs are believed to have signed a letter to Graham Brady, chairman of the 1922 Committee of backbenchers, calling for a leadership contest, although he refused to tell anyone what the number was at a meeting of the executive last week.
Another 15 to 20 are believed to be considering doing so, but, in the words of one colleague, "will almost certainly be too cowardly when it comes to it". Brady must have 46 letters before a leadership contest is triggered. The word is that the dozen signatories are from all wings of the parliamentary party, reflecting a spectrum of discontent. The right wants Cameron to give a referendum on Europe and commit to the seizing back of more powers from Brussels. It is unhappy with the pro-EU Lib Dems and wants taxes cut and spending slashed even more. The left, on the other hand, is fed up that much of Cameron's "modernisation" agenda (including green policies) has been abandoned and at the self-inflicted damage of unpopular health service reforms.
Many Tory MPs say that following months of U-turns they do not know what to tell their constituents to believe in any more. They complain that the party has no direction. But even among the most critical there is, to date, no sign of a united view emerging about who might take on Cameron. The mini-revolt is more an expression of broad unhappiness than a well-formed plot with a clear plan of action behind it. Some like the idea of Johnson as leader because he would cheer up the party and be, initially at least, massively more popular in the country. Others from the right would like to see former defence secretary Liam Fox or David Davis taking over. There is also an idea being put around that a unity candidate might run and Brady's name is being mentioned. Such ideas provoke wildly mixed reactions. "I like old Graham," said one senior Tory. "But that is mad. He's a real plodder." The lack of coherence is, however, no reason for Cameron to rest easy. The leadership issue will not go away. As we report, Johnson, fresh from outshining Cameron at the post-Olympics rally, is planning a series of appearances both at the Tory party conference in Birmingham next month and afterwards during which he will focus on his successes in 2012 – securing re-election as London mayor in May and fronting the Olympics. The theme will be how Tories (under Johnson) can win against Labour when there is not much money around and how they can organise things (under Johnson) better than anyone else in the world. While the mayor will cast it all in a loyal frame, he – not Cameron – will be the darling of the conference.
Downing Street is edgy, to say the least, and its dismissive line that "serious times require serious people" is not likely to help. Johnson is bound to milk his conference appearance to the maximum. He will arrive on the Monday and attend a rally and a fringe, amid huge media attention. In the evening he is due to speak at an event staged by the ConservativeHome website, which is edited by Tim Montgomerie, a regular critic of Cameron. The event is entitled "Boris Johnson's 2012. Re-elected and Olympotastic". Then on Tuesday he will speak to conference once more on the themes of how to win in austerity and how to get re-elected against Labour. Provocative?
The mayor's biographer Andrew Gimson, author of Boris – the Rise of Boris Johnson, believes it is. It would, he says, be "quite out of character" for Johnson to miss this chance to upstage Cameron. "These occasions are perfect for such an operation: you have hundreds of journalists with nothing much to write about except for dreary speeches by careerists who reckon the way to get to the top is to stay on message. Boris reckons the way to get to the top is to go off message." The pattern of Johnson causing trouble was set at Cameron's first conference as Tory leader, in Bournemouth in 2006. Cameron praised the TV chef Jamie Oliver. Johnson then told a fringe meeting: "If I were in charge, I would get rid of Jamie Oliver and tell people to eat what they like." Again in 2009, he infuriated the leadership by playing to the Eurosceptic gallery with calls for a referendum, just as Cameron was trying to sweep the issue under the carpet in the runup to the general election. Finally, on 7 November, Johnson will address the 1922 Committee, where another thunderous reception can be expected, at the invitation of Brady.
Johnson's autumn addresses will unsettle Cameron, who is already worried that others around him, including education secretary Michael Gove, are manoeuvring. A cabinet minister said last week that the word was that the PM deliberately sacked two of Gove's ministers in the reshuffle without his say so because Gove had leaked several policy stories without telling No 10 first. It was a message about who was running the show.
With both party leaders vulnerable, the party conference season presents them with tactical challenges and dilemmas. Some in the Tory party think the threat from Johnson will make Cameron move further to the right and persuade him to take harder lines on Europe, on immigration and on crime, while backing deeper spending cuts to get the deficit-cutting strategy back on track. The reason would be to buy some time with the parliamentary party, where the right is larger and more vociferous than the left. But that approach will have other knock-on effects that will not help the prime minister and the coalition.
Most of all it will make it even more difficult for Clegg to persuade his party that it can deliver on Lib Dem values and policies in a coalition with Cameron's rightward-drifting Tories. At the Lib Dem conference in Brighton, which begins on Saturday, Clegg will have to stand firm against Cameron on Europe, on the environment, on civil liberties, on preventing further cuts in welfare, because if he doesn't his party could well ask whether it is all worth it, and turn against him.
And where will it turn? Increasingly, perhaps, towards Cable, who is beginning to talk more and more with Labour about future co-operation. Those text exchanges with Ed Balls will become more regular. The real problem for Cameron and Clegg is that, in seeking to keep their own parties united behind them in the face of leadership threats, they may have to take them in opposite directions. The bigger question then becomes whether the coalition can survive the strain.
guardian.co.uk © Guardian News and Media Limited 2010
image: © BackBoris2012