The Conservative-Lib Dem coalition has "effectively expired" and should be ditched to allow the Tories to campaign for an outright majority, two senior Conservatives hae said.
Witham MP Priti Patel said that the reason for the coalition's existence has now "effectively expired", while Lord Tebbit said "the sooner it is broken up, the better".
Their comments are among contributions to a Bow Group publication which will make the case for ending the coalition and continuing as a minority Tory administration.
They were released on the day of the Conservative Spring Forum in London, ahead of their publication next week in the thinktank's magazine Crossbow.
In his contribution, Lord Tebbit wrote: "The coalition is beginning to smell past its sell by date, and the sooner it is broken up the better, never to be returned to."
David Cameron had "no excuses" for failing to win an overall majority in the 2010 general election, and his efforts to win Liberal Democrat support have "reinforced the conviction of Lib Dem voters that the Lib Dems were right, but left many of our own voters feeling lost", wrote the former party chairman.
Patel said: "With growth this year predicted to be 2.7%, record numbers of people are in work as unemployment falls, and welfare bills are being capped. The closing of the opinion polls on the back of the Chancellor's brilliant Budget in March, which included reforms to pensions and savings and cuts to green levies, demonstrates that the public like Conservative policies and want more.
"Crucially, this means that the reason for the coalition being established - Liberal Democrat support in the House of Commons to ensure that our programme of economic reforms can be implemented - has now effectively expired."
Other contributors to the publication include the chairman of the Conservative Voice group Don Porter, who said that the party's priority over the next 12 months should be to present "a clear and undiluted view of what a Conservative government will deliver in order to win back the core support that has been lost", adding: "If this means the break-up of the coalition in order to present such a platform, so be it."
Bow Group chairman Ben Harris-Quinney said: "Despite progress on the economy, genuine popular opinion and the sense of being the force behind a national movement have been lost by the Conservative Party, and at the current rate Ukip will overtake the Conservative Party as a membership organisation within seven years.
"At least to the country at large, it will be impossible to define our own ideology as a party whilst in coalition with the Liberal Democrats, and if we can't do that before the next election, it will be impossible to win a clear and Conservative majority.
"That is why we call for the dissolution of the coalition Government, to allow the Conservative Party a year to set out its stall to the country as a party of solid conservative ideology. A party of competence and long-term vision as well as short-term pragmatism."
Next week's publication will also include contributions from MPs calling for a return to more traditional Conservative values, while stopping short of advocating an end to the coalition.
These include minister without portfolio John Hayes, who said Britain had been most successful when it was "most confident about our shared values and our common culture", Bury North MP David Nuttall, who said that coalition Government had thwarted hopes of "Conservative-led common sense reforms" and described the Lib Dems as "not natural bedfellows", and North Enfield MP Nick De Bois, who said: "We're in coalition now, but we don't want to be in May 2015 and the Conservative manifesto for 2015 needs to inspire Britain that we can see the way forward."