Leading underwriting agency Select & Protect has attacked high street mortgage company Halifax for failing to disclose property rebuilding costs in valuation surveys.
Currently, when Halifax customers have valuations carried out, they do not know what the rebuilding costs are likely to be.
Select & Protect claims customers find it difficult to shop or alternative insurance because with the majority of providers this is key data.
Select & Protect claims this is a deliberate ploy and a restrictive practice.
James Wallis, marketing director of Select & Protect, said: "Homebuyers pay for valuation surveys but are denied access to the information they contain.
"We have a particular problem with the Halifax, which claims that such information need not be disclosed because their premiums are not rated on this basis. This is a nonsense."
However, Halifax dismissed the accusations claiming that it had simply "moved on" in its insurance calculations procedures. A spokesman for the company said: "Insurance is calculated in a new way, a more sophisticated way. If others are unhappy about that, that is up to them."
He also denied that Halifax was not disclosing information to stop consumers shopping around. He said under improved systems, Halifax did not need rebuilding costs data to calculate insurance premiums.
He added: "This is not important data for us. If a customer doesn't like our insurance, all they have to do is contact Direct Line or whoever, the first question they will be asked is rebuilding costs, but if that can't be provided it is not a problem at all they just ask for other information."