Britain’s banks and building societies could absorb a 20 per cent fall in UK house prices in a year without further denting their capital reserves, according to research by Moody’s, the credit ratings agency.

The study, to be published on Friday, comes as shares in the UK’s largest lenders continued to slide on Thursday, raising fresh concerns that the investment banks that have underwritten the rights issues for Royal Bank of Scotland and Bradford & Bingley would be left holding a substantial proportion of the new shares.