Software glitches threatened yesterday to scupper the launch of Home Information Packs in June as ministers came under further pressure to delay the proposals.

Although the Tories failed to block the reforms in the Commons, the continuing dispute over the packs led to calls for a 12-month postponement.

The Times has learnt that faulty software has thrown many of the training programmes for energy inspectors into disarray. It emerged yesterday that IT programmes to measure home energy ratings have failed to analyse the correct data.

One estate agent told The Times that a huge number of energy inspectors will have been trained on faulty software. Although two suppliers have had their software approved, two others — Property Tectonics and Northgate — are said to be still waiting, two weeks before the deadline on June 1.

Critics, including the Consumers Association, said yesterday that pilot schemes to test the packs had not been evaluated and that the proposal should be delayed for at least a year.

The Government is facing a legal challenge over the plan after the announcement by Royal Institution of Chartered Surveyors (RICS) that it was seeking a judicial review regarding a lack of consultation.

The latest problems came amid reports of a row between Ruth Kelly, the Communities Secretary, and Yvette Cooper, her deputy, over the Home Information Packs. Mrs Kelly wanted to scale the proposals down, but this was strongly resisted by Ms Cooper, the Housing Minister, who reportedly threatened to resign.

A spokeswoman for Mrs Kelly last night denied that there had been a row with Ms Cooper. “It’s all a load of nonsense,” she said.

After June all those putting their homes on the market will be required to provide the information packs, with details of land searches, title deeds and an energy performance certificate. The proposal had intended to speed up house sales and to help first-time buyers. Ministers are now focusing on the energy certificates, claiming that they will reduce carbon emissions.

The Tories were defeated yesterday by 306 vote to 234 in their attempt to annul the regulations for the packs.

Michael Gove, the Conservative housing spokesman, said that the packs were waste of time and “would do nothing to take the strain out of home-buying, and only add to the cost and complexity of buying a house”.

“Ministers have botched this process from beginning to end. They have ploughed on, regardless of the potential damage that they are doing to the housing market at an acutely delicate time,” Mr Gove said.

John Prescott, the outgoing Deputy Prime Minister, accused the Tories of hypocrisy by opposing a measure that was designed to boost energy efficiency.

Ms Cooper claimed the plans were sensible and insisted that the Government had made changes in response to consultation. “We do think that these are the right measures to introduce this summer,” she said.

The housing industry, which claims that the packs may trigger a market collapse, remained opposed. Nicholas Leeming, director of Propertyfinder.com, said: “The original policy objective to speed up the home-buying process has been lost amid the hot air of an environmental battle. Quite apart from the cost, the reported lack of energy inspectors is likely to cause serious delays for people trying to sell their home. We are currently seeing a rush to beat the deadline, but post June 1 we are likely to see the number of properties on the market to go into tailspin.”

Dave Timms, of Friends of the Earth, said: “It is crucial that this vital measure is not delayed. We hope the Lords will also give their backing when they vote next week.”

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