Lenders came under renewed attack as figures showed an increasingly wide gulf between the cost of wholesale funding and the price of new mortgages.

The average interest rate of a two-year fixed-rate deal, the most popular type of mortgage amongst homeowners, has fallen by just 0.71 percentage points to 5.57 per cent since the beginning of October, according to Moneyfacts.co.uk, the financial website.

In the same period, two-year swaps, the money markets which banks use to fund fixed-rate mortgages, have tumbled by 2.61 percentage points. Two-year swaps fell to 2.65 per cent today.

Mortgage experts accused lenders of boosting profit margins at the expense of borrowers who are struggling to find competitive deals amidst a chronic mortgage drought. The total number of mortgages on the market has fallen by almost three-quarters since the beginning of the year. There are currently 2,022 deals available, compared to 7,931 in January.

Moneyfacts also gave warning that borrowers are being forced to opt for “expensive” fixed-rate deals because of the lack of availability of new tracker mortgages, which are pegged to the Bank of England base rate. Fixed-rates now account for 69 per cent of the market, compared to 51 per cent this time last year.

Michelle Slade, of Moneyfacts, said: “These worrying figures prove that lenders are increasing their margins, despite a fall in the cost of funding. All lenders are adopting a similar approach, despite calls from the Government to pass on cuts to borrowers.”

The Council of Mortgage Lenders (CML) predicted that net mortgage lending would become negative next year, as banks and building societies collect more in mortgage repayments than they lend in new home loans. It also reported that gross lending collapsed to £14.6 billion last month, down 22 per cent from October.

The CML recently attacked the Government for attempting to force lenders to pass on cuts in the Bank of England base rate to borrowers on variable-rate deals. It argued that banks and building societies should be allowed time to rebuild their capital position and protect the returns offered to savers, which have tumbled dramatically in recent months.

Abbey, the second biggest mortgage lender, has announced that it is cutting the cost of its fixed-rate deals by up to 0.6 percentage points today. It now offers a two-year deal fixed at 4.64 per cent with a £995 fee for borrowers with a 40 per cent deposit.

Aaron Strutt, of Chase de Vere Mortgage Management, a broker, said: “The outlook remains extremely gloomy. Attractive deals are only being offered to the most "prime" homeowners remortgaging with a sizable chunk of equity in their home. If the housing market is to recover, lenders must start providing cheaper deals to borrowers with smaller deposits."