Nick Clegg sought to reassure Liberal Democrats worried by the depth of the cuts as he insisted that the party's values were written through the spending plans "like the message in a stick of rock".
In a letter to party members yesterday, the Liberal Democrat leader said: "We have had to make some very difficult choices. But the review is one that promotes fairness, underpins growth, reduces carbon emissions and localises power."
Some politicians were reassured by George Osborne's assertion that the average 19 per cent cut in spending by non-protected government departments was less than Labour had envisaged.
But worries about some of the measures – such as cuts to child benefit and housing benefit – still surfaced among the party's MPs and activists.
Benjamin Ramm, editor of the Liberal magazine, said: "These cuts are as swift and savage as many Lib Dems feared and I know of no party member who will campaign to defend them."
He claimed: "This [spending] review marks the culmination of the Conservative project to dismantle the liberal infrastructure of the welfare state – and it signals the beginning of the end for the Liberal Democrats."
Bob Russell, MP for Colchester, raised fears that reductions to housing benefit entitlement would increase levels of child poverty. "Hundreds of thousands of families will be adversely affected by the removal or cutting of housing benefit. The social consequences of that can only lead to family upheaval and children being rendered homeless," he said.
Tim Farron, MP for Westmorland and Lonsdale, said he hoped some of the cuts to benefits would be regarded as temporary rather than permanent measures.
In his letter, Mr Clegg said: "We are not taking the decisions today because they are easy or because we want to see a smaller state, we are taking them because they are right. We have a hard road to recovery ahead, but we are determined to ensure it is a road that leads to fairness too."
He added: "Liberal Democrat ministers have fought to ensure that the burden of the challenge ahead is shared fairly."
His deputy, Simon Hughes, who is regarded as on the left of the party, insisted that the cuts had been as fair as possible. Urging against overreaction to the measures, he said: "There will be difficult times ahead in many households and communities and it would not be right to jump to conclusions about what the effect of today's decisions will be either nationally or locally. Liberal Democrats in national and local government will never give up our work to deliver a fairer society and make sure public services are always provided to protect the poor, the needy and the vulnerable."
Sir Menzies Campbell, the former party leader, welcomed the increases in spending on schools and hospitals, as well as the emphasis on investing in apprenticeships, science and transport infrastructure.
But Mr Clegg's argument fell on stony ground among some activists on the Liberal Democrat Voice website. One user, AlexKN, pointed to his leader's claim that the spending review was a "thoroughly Coalition product".
He retorted: "Yes, Nick and that's why I am wondering if I have spent 16 years building a Lib Dem presence in my area to have it shattered by your decisions about the Coalition."
Richard Heathcote said: "It is hard to see a difference between the Coalition and the Conservative Party to be quite honest. The Lib Dem message is being lost."
Pat Roche said that Danny Alexander, the Treasury Chief Secretary, could not justify the fact that the "bottom 10 per cent are bearing the brunt of the cuts", adding: "The public don't know what the cuts mean but they will.
"The Tories have set up the Lib Dem leaders, who sound and look like Tories – to sink without a trace at the next election, after, of course, they have dismantled society for the poor."
Register for free to continue reading
Registration is a free and easy way to support our truly independent journalism
By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists
Already have an account? sign in
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies