The Commons watchdog has admitted it made an error after temporarily blocking Iain Duncan Smith's credit card, used to pay some of his expenses.

He was among 19 MPs subject to action by the Independent Parliamentary Standards Authority over cards used to pay for travel and accommodation.

The Press Association reported that the work and pension secretary had run up more than £1,000 in expenses debts.

But IPSA said Mr Duncan Smith's card had been de-activated by mistake.

A spokesman for the cabinet minister said: "Iain has not had his card suspended. Ipsa have confirmed twice in writing that this issue was an error on their part. To be clear no money is owed".

A spokeswoman for Ipsa said: "I can confirm that the payment card in the name of Mr Duncan Smith is currently active. It was temporarily suspended in error and has since been reactivated."

Under the system, politicians have to prove their spending is genuine at the end of every month or build up debts to the watchdog and their cards can be de-activated once sums owed reach a certain level.

Among those MPs whose cards were stopped since the start of the year, according to an FOI request by the Press Association, were Labour's work and pensions spokeswoman Rachel Reeves and former Lib Dem minister Simon Hughes.

Both have since cleared their debts - which totalled £4,033,63 and £826.56 respectively.

'Recovery action'

Former Labour MP Eric Joyce, who assaulted a fellow MP in a Commons bar and received a suspended jail sentence in May following a separate incident, had his card blocked when he owed £12,919.61, and later had his salary docked.

Other MPs who had a bar put on their cards included Toby Perkins, Ben Gummer, Mark Lancaster.

Ipsa also revealed that 25 MPs and former MPs currently have sums outstanding on their cards, including the DUP's Iain Paisley and former Lib Dem MPs Mike Crockart and Stephen Gilbert.

An Ipsa spokesman stressed that these figures were a "snapshot" and in many cases could merely be awaiting evidence from MPs that they were valid claims.

"An MP may owe an amount to Ipsa for many different reasons, and the fact that an amount is owed does not, in itself, indicate any misuse of the MPs' Scheme of Business Costs and Expenses," the spokesman said.

"As part of our credit management programme, MPs are sent financial statements detailing their monthly position with Ipsa. Where MPs have amounts owed to Ipsa, action is taken to recover these amounts."