Conservative Leader David Cameron pledged on Saturday to rid Westminster of the whiff of sleaze that was turning the public against politicians.
"Let's be clear what they think of us: 'You lie and you spin, you fiddle your expenses and you break your promises'", he told activists at the party's spring conference in Gateshead.
"This isn't a mood. It cuts really deep. And we have to respond."
Gearing up party activists ahead of local elections in May, Cameron said the Conservatives had to win back the trust of voters who had grown cynical about politics.
"We will have to fight the real enemy. Not only Gordon Brown, but the cynicism, the apathy and disengagement that has left people so exasperated with government, politics and the whole Westminster merry-go-round."
Cameron has already ordered his front bench to disclose details of how they spend their allowances and which relatives they employ.
The move followed Cameron's expulsion of Tory MP Derek Conway from the parliamentary party following the disclosure he used taxpayers' money to pay a son for work he apparently never did.
"Let's not pretend that we're outsiders to Westminster come to clean things up. We've been part of the problem and we need to sort it out from within," Cameron said.
"This is public money, taxpayers' money, and it is our duty to be careful with it and open about how it's spent," he said to applause.
MPs were criticised last week after it was revealed they could claim up to 22,000 pounds on household items to furnish a second home outside London.
A special Commons committee chaired by the Speaker Michael Martin is reviewing expenses in the wake of the Conway affair.
Last week the committee told MPs they would have to provide receipts for everything they spend over 25 pounds, down from the current threshold of 250 pounds.
