Party reaction: Liberal Democrats fear deal will provoke exodus

Unease at prospect of sitting alongside Conservatives

Tory and Liberal Democrat backbenchers were coming to terms with the prospect of sitting alongside MPs from a party they had spent their careers fighting yesterday, amid signs of grassroots unease over the formation of the historic coalition.

Even the most outspoken MPs in the parties were holding their tongues as they were determined to present a united front backing the deal. However, Liberal Democrat MPs admitted the party would lose supporters who would not understand Nick Clegg's decision to form a full coalition government with the Tories. There were also signs of frustration within Conservative ranks over David Cameron's failure to secure an outright majority.

Liberal Democrats on the left of the party were still picking over the bones of the failed attempt to form a "progressive alliance" with Labour yesterday, with many still fuming at the refusal of Gordon Brown's negotiating team to make any serious compromises. "Obviously, there was a gut reaction from many of us about working with the Tories, but the response from Labour made the difference," one said. "The Tories have been far more progressive in what they were offering us than Labour, who were pathetic."

Even the most anti-Tory figures conceded that the coalition with the Conservatives had become the only option. "We were left with no choice and we must now make this work," said one, who had given up a role as a junior department spokesman. They anticipated that problems would emerge when senior Liberal Democrats were asked to justify tougher policies pushed through by Mr Cameron.

Jim Wallace, who helped negotiate Lib Dem coalition deals in Scotland, has been working behind the scenes on the mechanics of the agreement in a bid to allay the fears of Liberal Democrat backbenchers. "We are naturally suspicious of the Tories and they are naturally suspicious of us," said one MP. "But Jim's involvement has helped a lot." Many were still amazed at the concessions made by the Tories. "We're trying to work out exactly why they gave us so much," said another on the left of the party. "Maybe it's because Cameron is for real. Maybe we're useful to help him with the right of his own party."

Don Foster, the party's MP for Bath, said its grassroots operation would be hit by the advent of the coalition. "I think there is no doubt whatsoever there will be party members who will walk away, because they want the total purity, but I have to say to them that if we have a situation like this, we have a responsibility to find a way forward that is in the best interests of the country. Of course it will be difficult for Liberal Democrats, including me, to swallow having to work with people who we were campaigning against, but the electorate asked us to do that and that's what we will have to deliver."

Some party members did see the coalition as a mistake, but most were taking a pragmatic approach. "This is going to be extremely difficult. It's definitely not the choice I would have made," said Mark Bailey, a councillor in Bristol, a city in which the Liberal Democrat MP, Stephen Williams, had fought off a challenge from the Tories. "Any policies that are successful, the Tories will claim all the credit. It's a lose-lose situation for us."

One prominent Tory backbencher said he would keep his "powder dry" while he waited to see how the coalition worked out. But some admitted in private that Mr Cameron's "Big Society" pitch had been too complicated to explain on the doorstep. In a survey of more than 3,000 party members by grassroots website, ConservativeHome.com, more than 62 per cent said they believed the Tory election campaign had been "poor".