John Bercow, a former Shadow Cabinet member, launches a strong attack on the policy on which Michael Howard fought the general election and argues that migrants are good for the economy and the British people.
Writing in The Independent, Mr Bercow says the Tory policy was "wrong for the country and damaging to the attempted recovery of the party". He says "a more balanced approach would cause many voters, who reject the party, to think of us afresh".
Although many senior Tories accept the need for the party to change after a third successive defeat, Mr Howard defended his hardline approach on immigration in his farewell speech at the Blackpool conference, and said the party should not be silenced on the issue.
Mr Bercow, who is supporting Kenneth Clarke in the Tory leadership race, says the party's call for an annual limit on immigration should be dropped. Instead, it should improve the points system for assessing would-be migrants which the Tories proposed and has been adopted by the Government.
In a pamphlet published by the Social Market Foundation think-tank, he lambasts the Tory plan to pull out of the 1951 United Nations Refugee Convention and impose a cap on the number of refugees entering Britain as "arbitrary and cruel", and warns it would turn the UK into a "pariah state". He says: "The policy was as misconceived and unattractive as any the Conservative Party has proposed in recent times." Describing his party's stance as "narrow, dogmatic and unrealistic," Mr Bercow say it is "wrong and dangerous" to dismiss asylum-seekers as economic migrants.