House prices could fall by as much as 25 per cent from their 2007 peak and will not recover until 2010, according to the head of Nationwide.

The chief executive of the mortgage lender Graham Beale told the BBC a typical British house would have decreased in value by a quarter by 2010.

According to the news provider, this would put 2.5 million homeowners in negative equity.

He said: "I think that next year we will see a similar pattern to this year ... we will see further falls in house prices."

The UK''s largest building society has increased its customer base to around 15 million after merging with Cheshire and Derbyshire building societies, both of which recorded pre-tax losses as a result of bad debts and "financial issues".

Mr Beale said Nationwide was in a unique position to provide support to the building societies.

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