Credit card firms have been accused of punishing thrifty borrowers by increasing interest rates to recoup revenue they lost following a clampdown on late-payment fees.

In April 2006, the Office of Fair Trading said that the charges levied when people miss their credit card payments were unfair forcing providers to cut penalty fees to £12 or less.

Since then, the average purchase rate has risen from 14.9 per cent to 16.4 per cent as lenders look to claw back the lost revenue, says Moneyfacts.co.uk, the financial information website.

Michelle Slade, an analyst at Moneyfacts, says: "Previously whereas only a select number of customers were being penalised, now all borrowers are paying the price. With many households struggling with increasing financial pressures, those who only repay the minimum will be hardest hit.”

Anyone with a balance of £5,000 repaying just 2.5 per cent per month will end up paying an additional £755 in interest, Moneyfacts claims.

Other costs have increased too. Average rates for using a card to withdraw money from cash machines have risen from 18.1 per cent to 24.3 per cent. Most providers have also increased their cash advance charges from 2 per cent to 3 per cent.