Arrested MP accused of 'grooming' mole

The Conservative MP Damian Green was accused by police of "grooming" a Home Office mole. The accusation came during nine hours of questioning by police investigating at least 20 leaks of secret documents from the department. As details of the investigation emerged, the shadow Immigration minister told friends he was livid that detectives resorted to "provocative" language used to describe sex offenders and suicide bombers.

Whitehall officials fear that a minimum of 20 confidential papers are believed to have been spirited out of the Home Office in the past 18 months, far more than the four leaks originally linked to Mr Green.

The outcry over his arrest left Michael Martin facing the worst crisis of his eight years as Commons Speaker as senior MPs of all parties demanded as explanation over why police were allowed to raid Mr Green's parliamentary office. The events have caused turmoil in Scotland Yard, with the Acting Commissioner of the Metropolitan Police, Sir Paul Stephenson, understood to be considering withdrawing his application to succeed Sir Ian Blair as commissioner.

Mr Green was arrested on Thursday by police probing his links to a junior Home Office official suspected of leaking a succession of documents that embarrassed Jacqui Smith, the Home Secretary. The episode has led to furious protests from across the political spectrum that he was being pursued just for doing his job of holding the Government to account. Ms Smith is also under fire from some Cabinet colleagues for her handling of the affair.

Evidence of the aggressive questioning faced by the Tory MP during his grilling in Belgravia high-security police station were disclosed last night by party sources. One said: "He was accused of 'grooming' a civil servant. He was very angry about the choice of word and did not reply to the question. He thought the police were being deliberately provocative. It typifies the cack-handed way they are handling the investigation."

The source said Mr Green was feeling "very robust" and would not be deterred from his parliamentary work, although his telephones and computers have been seized by police. Mr Green was questioned by police investigating whether he incited the Home Office official, who was named yesterday as 26-year-old Chris Galley, to leak documents. He has told friends he is adamant he has done nothing wrong.

Ms Smith refused to apologise for the arrest as she signalled that the investigation was more wide-ranging than previously suggested. "This started as an investigation of a systematic series of leaks from a department that deals with some of the most sensitive and confidential information in government," she said on BBC1's Andrew Marr Show.

But Harriet Harman, the Commons leader, struck a more conciliatory note. She said she was "very concerned" by the police action and called on Speaker Martin to examine the procedures for allowing raids on Parliamentary offices. "We have got to be sure that while MPs are not above the law, that actually they are able to get on with their job without unwarranted interference by the law," she told Sky News. "These are very, very big constitutional principles. We have to make sure they are protected."

The Speaker's critics, joined yesterday by the former cabinet minister Kenneth Clarke, are demanding an explanation over why the raid was allowed in the Commons. Richard Bacon, the Tory MP for Norfolk South, said: "It leaves me wondering how I can have any confidence that the Speaker would defend my right as a Member of Parliament to hold sensitive information without the fear of a police raid."

Some MPs are even threatening to disrupt the Queen's Speech ceremony on Wednesday marking the new parliamentary year to highlight their anger.

Mr Martin is expected to make a statement to the Commons on the episode that day when MPs return from a brief recess.

Home Office leaks: The police investigation

*May 2004 Chris Galley stands as a Tory candidate in 2004 elections for Sunderland Council. Polls 676 votes.

*Dec 2005 Damian Green is appointed the shadow Immigration Minister by the new Tory leader, David Cameron.

*Mid-2007 Mr Galley applies to work for Damian Green but is rejected.

*July 2007 Jacqui Smith is appointed Home Secretary.

*Nov 2007 Leaked memos suggest Ms Smith helped cover up licensing of illegal immigrants as security guards.

*Feb 2008 Home Office document discloses an illegal immigrant worked at the Commons using a fake pass.

*April 2008 Sunday paper passes a Home Office list of more than 50 Labour MPs suspected of plotting to defeat plans to extend detention the period for terror suspects to 42 days.

*Sept 2008 A leaked letter from Ms Smith to Downing Street reveals fears the recession will increase crime.

*Sept/Oct 2008 The Permanent Secretary at the Home Office, Sir David Normington, asks for police help in identifying the mole.

*19 Nov 2008 Mr Galley is arrested at home during a raid and is suspended.

*27 Nov 2008 Mr Green is arrested and questioned. Sir David, Mr Cameron and Boris Johnson informed. Police gain permission from Commons authorities to enter Palace of Westminster. Mr Green's offices and London home are raided. Mr Green released at 11pm and denies any wrongdoing.

*28 Nov 2008 Police remain at Mr Green's offices in Ashford, Kent. Both Gordon Brown and Ms Smith insist they knew nothing in advance of the police action. The Tories release list of 40 unanswered questions over the episode for Ministers, Scotland Yard and the Commons Speaker.

*Yesterday Mr Cameron brands Mr Brown a "hypocrite" for his silence over the arrest and says it is a "watershed moment" for democracy.

*Wednesday Angry MPs to return to the Commons for the Queen's Speech. Michael Martin, the Speaker, is expected to make a statement.

*Jan 2009 Mr Galley is due to return to police for further questioning.

*Feb 2009 Mr Green is due to return to police for further questioning.