Many credit card users have had their credit limit increased without requesting it, new research has shown.

A study by consumer magazine Which? Money revealed 71 per cent of credit card users had been given an unsolicited rise in their credit limit while 62 per cent had been sent credit card cheques without requesting them.

Research published recently by price comparison site uSwitch.com warned that 313 million credit card cheques were issued last year without being requested.

This form of credit is usually more expensive than using a credit card and Mike Naylor, personal finance expert with the site, said the findings raise questions about the providers’ commitment to responsible lending.

He said: "It is easy to see how credit card cheques can appear a very attractive option for borrowers who are desperately in need of money."

Borrowers who use such credit as a "quick fix" could end up with a "serious financial hangover", concluded Mr Naylor.