Media playback is unsupported on your device Media caption Sir Malcolm Rifkind: "I don't think I did anything wrong. I may have made errors of judgement. That's a different matter."

Sir Malcolm Rifkind is stepping down as chairman of Parliament's Intelligence and Security Committee after criticism over "cash-for-access" claims.

The former foreign secretary is also standing down as a Conservative MP.

Sir Malcolm and Labour MP Jack Straw were secretly filmed apparently offering their services to a private firm for cash. Both deny wrongdoing.

Commons Speaker John Bercow said the two MPs would be punished if they were found to have broken the rules.

Announcing his decision to step down, Sir Malcolm said he did not want the committee's work to be "distracted or affected".

He and Mr Straw, also a former foreign secretary, featured in the undercover investigation by the Daily Telegraph and Channel 4's Dispatches.

Both MPs have referred themselves to Parliament's standards watchdog and both deny breaching House of Commons rules.

'Lack of support'

Sir Malcolm, the Conservative MP for Kensington, had previously said he would not stand down as security committee chairman, unless his colleagues wanted him to.

The BBC's political editor Nick Robinson said Downing Street withdrew its support from Sir Malcolm and "threatened to push [him] if he didn't jump first".

In a statement issued on Tuesday morning, he said while he would remain a member of the committee, he would step down from the chairmanship.

The committee is due to publish a report next month looking at surveillance by the intelligence agencies, and Sir Malcolm said he had decided "it is better that this important work should be presided over by a new chairman".

The Intelligence and Security Committee released a statement Tuesday evening saying it would not elect a new chairman before the election.

The committee said that "all further matters" which arise between now and the end of the Parliament "will be dealt with by the committee as a whole".

Political career

Image copyright PA Image caption Malcolm Rifkind was foreign secretary in John Major's government

Sir Malcolm Rifkind, 68, was born in Edinburgh and worked as an advocate before being elected as MP for Edinburgh Pentlands in 1974, representing the constituency until 1997

He was appointed to Margaret Thatcher's first government in 1979, and joined the Cabinet in 1986 as Scottish secretary

In 1992 he became defence secretary in John Major's government, implementing widespread cost-saving measures to his department, and was made foreign secretary in 1995

Having lost his seat at the 1997 election, he returned to Parliament in 2005, representing Kensington and Chelsea in London, and made a short-lived attempt to replace Michael Howard as Conservative leader

As chairman of the Parliamentary Intelligence and Security Committee, which oversees the UK's intelligence agencies, he has been heavily involved in the debate over privacy and surveillance powers

Speaking after a meeting of the committee, Sir Malcolm told BBC News he did not believe the allegations against him were "justified".

"I did not want the work of the committee to be distracted," he said.

"It's quite obvious that, fairly or unfairly, this has become an issue."

Labour is calling on the other parties to back a motion in the Commons on Wednesday banning MPs from taking paid directorships or consultancies.

'Cop it'

A Labour spokesman said: "David Cameron once promised change but now defends a discredited status quo and has refused to follow Ed Miliband's lead. This is his chance to vote for an important measure which would help restore trust in politics."

Sir Malcolm's predecessor, ex-Labour MP Kim Howells, had increased pressure on him by warning that the committee's work must not be "dragged down".

Reacting to Sir Malcolm's decision to step down, Mr Howells told Sky News he had "done the right thing".

During conversations with the undercover reporters, who posed as representatives of a fictitious Chinese company, Sir Malcolm had described himself as "self-employed", saying "nobody pays me a salary".

Mr Bercow, the Speaker of the Commons, told Sky News's Stand Up Be Counted campaign that MPs should not be in Parliament "to add to their personal fortune".

He said of Sir Malcom and Mr Straw: "They are both highly intelligent, highly capable, highly experienced people. It may well be that errors of judgment have been made," adding: "If that is so, then they will cop it, they will face the music, they will suffer a penalty as a result."

'Contemptible' allegations

Reacting to the story in the Daily Telegraph, he said his comments had been a "silly" thing to say, but questioned whether an MP's £67,000 salary was enough to attract people from a "business or professional background".

Announcing his decision to leave Parliament after May's general election, Sir Malcolm said the allegations against him were "contemptible" and that he had previously planned to seek one further term as an MP.

"I have concluded that to end the uncertainty it would be preferable, instead, to step down at the end of this Parliament," he said.

"This is entirely my personal decision. I have had no such requests from my constituency association but I believe that it is the right and proper action to take."

A Conservative Party spokesman said: "Sir Malcolm has had a long career of distinguished service both to the Conservative Party and the country. We respect and support his decision to stand down."