The Tories have demanded the government scrap its forthcoming house sale information packs, saying they could cost homeowners up to £1,000 each.
The new packs could depress the housing market, critics warn
They are using an Opposition Day debate in the House of Commons to show "profound concern" over the controversial house sale packs.
The Tories say there has been a lack of preparation for the packs, due to start in England and Wales in June 2007.
Ministers insist it will speed up sales and make the process cheaper.
The Conservatives' campaign features TV presenter Kirsty Allsopp, of Channel 4's Location Location Location, along with the Tory housing spokesman Michael Gove.
"If people trust these dodgy home information packs, I fear they will be lulled into a false sense of security," said Mr Gove.
"If they don't and commission their own survey, costs will be duplicated."
The new law will require sellers to assemble, at their own cost, a pack including title deeds, local authority searches, answers to standard questions and a home condition report, all of which will be given to any potential buyer.
The aim is to knock weeks off the normal house-buying process, reduce the scope for gazumping and to make sure that fewer deals fall through.
The government says they will cost about £650 for each seller to put together, but save buyers £1m a day, which they currently waste in aborted transactions.
A survey by Oxford Economic Forecasting suggested the packs might cost more, about £1,000 each, and that their use could lead to more unemployment and depress spending.
The Daily Mail newspaper reported that ministers wanted an urgent review of the programme after warnings it could adversely affect the UK's housing market.
It said 125 MPs, including former Labour ministers Frank Field and Kate Hoey, have signed a cross-party Commons motion asking Chancellor Gordon Brown to axe the house sale packs.