HBOS, Britain’s biggest mortgage lender, revealed that 381,669 customers, about 16.8 per cent of its mortgage book, owed more than the value of their homes. At Lloyds TSB, 162,000 homeowners, 15 per cent of its mortgage book, were in the same position. These figures compare with only 0.1 per cent of customers of each bank – a total of less than 4,000 households – being in negative equity at the end of 2007.