Spend, spend, spend ... or get a £20 bill for your Barclaycard

A million Barclaycard holders who use their cards infrequently or do not spend enough on them face charges of up to £20 a year.

Other banks have already imposed the charge but not on anything like the scale announced by Barclays, which is the country's biggest card issuer.

Barclaycard, with 8.4 million customers, issues one in every five credit cards in Britain.

Critics say the trend towards annual charges is killing off free banking by stealth.

Lloyds TSB recently introduced a similar annual fee of £35 for just 50,000 customers while Morgan Stanley is to charge thousands of its Black card customers £20 from June 1.

Fees of £24 have also been levied on Co-operative Bank's Platinum and Northern Rock's Base Rate Visa cards.

The Royal Bank of Scotland/NatWest group also fines card customers £12 for failing to alert it to a change of address. It has also introduced higher interest rates on cash withdrawals.

Banks are rewriting the rules on credit cards after they were forced to slash illegal and unfair penalty charges for those who miss payments.

Last year, the Office of Fair Trading told them to cut charges of around £25 to a maximum of £12.

Nick White, of comparison website uSwitch.com, said: "The problem is the transparency displayed around the criteria to select the customers charged.

"Without this, customers don't know how to manage their credit card account to ensure they do not fall into this category in the future.

"Lloyds TSB's move to implement a charge of £35 for customers who displayed low usage was a prime example of this.

"We're still no wiser as to how they chose these customers."

Barclaycard said: "We will do everything we can to improve the deal we give people and avoid fees.

"As a last resort, we are considering a fee for a minority that simply do not use their card. We expect the amount to be between £10 and £20."