The Law Society has accused some agents, based in England and Wales, of beginning to market homes without having ordered the Hip - which is mandatory for all property sales.

The packs - known as Hips - were introduced a year ago and were made compulsory for all homes put on the market in England and Wales in December, with the aim of providing potential buyers with greater transparency.

Speaking to BBC Radio 4's Today programme, Law Society president Paul Marsh said: "The evidence is that these Hips are being ordered and not being processed. They are being suspended until such time as a buyer is found.

"I don't think it is within the spirit of the regulations. Actually, I don't think it is within the regulations."

It is believed that in the present market sellers are reluctant to pay as much as £400 for the packs, which include an energy performance certificate and recent planning and building consents.

Independent reports have found that up to one in 10 properties are being sold without the pack included.