Property and legal experts have accused ministers of failing to take their concerns about the introduction of Home Information Packs (HIPs) seriously.
The government says HIPs will given buyers extra security
A group including the Law Society and Council of Mortgage Lenders said ministers had declined a meeting to discuss their concerns about the plan.
HIPs will become compulsory for all sellers in England and Wales on 1 June.
But the group said they were "seriously flawed" and would have a "devastating impact" on the housing market.
'Ineffective and impractical'
"In their current format, HIPs will prove to be ineffective and vastly impractical," said Charles Smailes, president of the National Association of Estate Agents, one of four organisations to have written to Tony Blair and Gordon Brown about the issue.
"I once again urge the government to work with the stakeholders and take note of our very real concerns."
The government believes HIPs, which will require sellers to have surveys and local authority searches done before putting properties up for sale, will speed up the selling process and give buyers added protection.
But the body which will represent firms providing HIPs said it had strongly reassured ministers that their introduction would be handled "effectively and efficiently".
"Calls from those who wish to see delays should be ignored by ministers, who should feel confident in delivering this consumer and environmental reform on June 1," said Mike Ockenden, director-general of the Association of Home Information Pack Providers.