Conservative Party chairman Caroline Spelman invited new Liberal Democrat leader Nick Clegg to join a "progressive alliance" to kick Gordon Brown out of office.
The Meriden MP issued the invitation after Mr Clegg beat leadership rival Nick Huhne by just 511 votes yesterday. The result was closer than expected and followed the resignation of former leader Sir Menzies Campbell.
Conservatives and Liberal Democrats already work together in local authorities, including Birmingham.
Mrs Spelman's latest overture followed an offer from Tory leader David Cameron, rebuffed by Mr Clegg yesterday.
The new Lib Dem leader said: "I want a new politics, a people's politics.
"I refuse to believe the only alternative to a clapped-out Labour Government is a Conservative Party with no answers."
Conservative calls for unity are designed to
pave the way for a possible coalition in a hung Parliament.
Mrs Spelman said: "We hope the Liberal Democrats under Mr Clegg will join us in putting pressure on the Government to devolve power to local authorities, communities and individuals; in our opposition to ID cards; and in our commitment to social justice and environmental progress."
"We hope together we can create a new progressive alliance to decentralise politics."
Mr Clegg, 40, beat Mr Huhne, the party's environment spokesman, by 20,988 to 20,477. A postal ballot of the party's 65,000 members closed on Saturday following a series of head-to-head hustings.
Following the announcement, the new Lib
Dem leader said he had "one simple ambition: to change Britain to make it the liberal country I believe the British people want".
He went on: "I believe liberalism is the thread that holds together everything this country stands for.
"Pull out that thread and the fabric of our nation unravels. So why is Britain still not the liberal Britain we want?
"Our civil liberties casually cast aside; giant faceless and incompetent Government bureaucracies; families struggling to meet monthly bills; struggling to balance the demands of work and family life. Our politics is broken - out of touch with people."
Although Sheffield Hallam MP Mr Clegg was widely seen as being further to the right than his rival, the relatively low-key campaign revealed little in the way of policy differences between the two contenders.
Mr Clegg capitalised on his reputation as an effective and telegenic communicator who could boost the party's public profile, while 53-year-old Mr Huhne highlighted his experience outside politics in finance and journalism.
The biggest policy spat came when
Eastleigh MP Mr Huhne said he would scrap Britain's Trident nuclear deterrent, while Mr Clegg said he would keep it at least until dis-armament talks in 2010.
The contenders fell out over a briefing note produced by Mr Huhne's campaign team - apparently without his knowledge - branding his rival "Calamity Clegg".
But last night Mr Huhne congratulated his rival, saying: "I look forward to participating as part of Nick's team to make sure the party goes from strength to strength. This party is going to see even greater successes in the future."
West Midlands Lib Dem MEP Liz Lynne said: "It was a very close contest which demonstrates that we had two very good candidates. I know Nick will make an excellent leader and will take us to even greater success in the future.
"He has pledged to reach out to people outside the party and I know he will be able to do that and we will go from strength to strength." :