Shares in Northern Rock plunged by almost a quarter this morning after the stricken lender said third-party proposals so far make shareholder value "highly uncertain", and the UK Treasury warned bidders the £20bn (€28bn)-plus loan package the lender received from the Bank of England may not be available following its sale.

Rock confirmed in a statement today that proposals received by Friday, which included plans to acquire parts of its business as well as investment proposals, implied a range of values "for the existing equity materially below the market price at the close of business of November 16".