Bradford & Bingley, the nationalised lender, conceded on Thursday that it would take some years to run down its £42.2bn loan book and said it would consider disposing of assets to achieve that end.

Publishing its 10-year business plan, B&B said it recognised that its loan book might be slow to run down because some existing borrowers have high loan-to-value ratios or hold buy-to-let mortgages and so cannot refinance easily with other mortgage lenders.