When some of Bradford & Bingley's largest shareholders stepped in to rescue the ailing mortgage lender's £400m rights issue last week, they agreed to help underwrite the share offering at a price of 55p. But other investors are coming to the conclusion that the bank's true value is much lower.

Shares in B&B on Tuesday slumped a further 8p to close at a new low of just 34p, as investors increasingly questioned the bank's long-term profitability and expressed scepticism about the possibility that a buyer would be found in the near term.