David Cameron has been urged to shift to traditional Tory policies following a surge in the polls by Labour.
Labour has seen an increase in support in newspaper polls
MP Edward Leigh, of the Cornerstone Group of right-wing Tory MPs, said Mr Cameron should focus on taxation, deregulation, immigration and defence.
However, Michael Gove, an ally of Mr Cameron, insisted the Conservatives were heading the right direction.
Two newspaper polls have recorded an increase in support for Labour since Gordon Brown became prime minister.
Mr Leigh told BBC Radio 4's Today programme: "The way that we fight back is to show that we are not weak, we are not driven by PR, we are a party of principle.
"As a matter of great urgency now, we ought to develop those policies.
"There's only one way they can go, which is the traditional Conservative way, the right policies, the progressive policies of successful countries around the world of low taxation, deregulation, strong immigration controls, strong defence and building on the social responsibility theme of David Cameron."
He added: "The fact is that traditional policies of all successful Conservative governments since the Second World War have all been much the same."
Former Tory Cabinet minister Michael Portillo told the programme Mr Cameron was doing the right thing.
He said "It is a moment of crisis, or at least a critical moment, in that it is very important that David Cameron should see off the people who want to undermine the strategy to position the Conservative Party on the centre ground.
"Many people like what David Cameron is doing, but they are not convinced that the party is following him... David Cameron has to take the party to the centre."
A Guardian poll showed a seven point increase in support for Labour since last month to 39%, to the Tories' 35%.
A survey for the Daily Telegraph found a five-point rise for Labour to 38%, against 35% for the Conservatives.
In a survey for BBC One's Politics Show, 40% said that Mr Brown's government would be "a change for the better" and 14% thought it would be "a change for the worse".
Conservative housing spokesman Mr Gove said: "Elections are won on the centre ground and David Cameron will win the next election by sticking to the centre ground.
"The majority of Conservative Party activists and members recognise that David Cameron is taking us in the right direction."