Banks and building societies have failed to pass on December's one percentage point rate cut to many borrowers while imposing swingeing rate cuts for savers, figures indicate.

Data published today by the Bank of England show that the average two-year fixed-rate mortgage deal for a borrower with a 25 per cent deposit fell by only 0.31 percentage points to 4.79 per cent last month, while the cost of a five-year fixed-rate deal fell by only 0.16 per cent.

Borrowers on a standard variable rate (SVR) were more likely to benefit, with the average SVR falling by 0.96 percentage points to 5.38 per cent, although this is still far higher than the current bank base rate of 1.5 per cent.

Savers saw their returns fall sharply last month as the returns on fixed-rate bonds plunged from 4.03 per cent to 3.02 per cent.

Those with cash in instant-access accounts saw their returns fall to an average of 0.8 per cent, down from 1.6 per cent.

This means that they are losing money in real terms as the current rate of inflation is running at 4.1 per cent.