Speaker faces showdown over raid on Tory's office

Michael Martin, the Commons Speaker, faces an unprecedented revolt from some of Britain's most senior politicians as the row over the arrest of Damian Green threatens to overshadow one of the great ceremonies of state today.

The affair was set to eclipse Gordon Brown's announcement of his plans for the new parliamentary year with senior opposition figures making clear they would demand an emergency debate into the police raids which have left MPs furious.

Opposition heavyweights, including the former party leaders Michael Howard and Sir Menzies Campbell, as well as the former chancellor Kenneth Clarke, are planning to disrupt today's Queen's Speech debate, which would overshadow one of the centerpieces of the parliamentary calendar.

There were increasingly bitter recriminations yesterday over the heavy handed treatment of Mr Green over his links with a Home Office mole, with Scotland Yard forced to announce an internal inquiry into its handling of the case. The Conservative Party released pictures last night of the moment that police broke hundreds of years of parliamentary tradition by raiding the shadow Immigration minister's Westminster office.

Mr Martin is due to make a statement to MPs at the beginning of today's debate on the Queen's Speech marking the beginning of the new parliamentary year. MPs of all parties are livid that he did not forbid the raid.

If he fails to grant an emergency debate, senior Tories and Liberal Democrats have been lined up to protest on the Commons floor. They include Mr Howard, the former Tory leader, Mr Clarke, the former chancellor and David Davis, the former shadow home secretary. They will be joined by Sir Menzies, the former Liberal Democrat leader. Mr Davis said: "Those around the House are bubbling with indignation over what's gone on."

David Cameron, the Tory leader, and Nick Clegg, the Liberal Democrat leader, held talks yesterday on presenting a united front. The opposition parties insist they will not disrupt the ceremonies in Westminster, when the Queen opens the parliamentary session. They have decided that a protest that embarrassed her would backfire.

Jacqui Smith, the Home Secretary, is preparing to make a Commons statement on the issue.

The pictures of the raid show Andrew Mackay, a key aide to Mr Cameron, remonstrating with counter-terrorism officers – one wearing purple rubber gloves – as they prepare to search Mr Green's office. Dominic Grieve, the shadow Home Secretary, said: "These pictures document a dark day for democracy."

The Metropolitan Police, stung by accusations the operation was "Stalinesque", announced an inquiry into officers' conduct in the investigation.

Mr Green was held and questioned for nine hours last Thursday after the earlier arrest of Christopher Galley, a junior Home Office official accused of repeated leaks. The Met inquiry will be conducted over the next two weeks by Ian Johnston, the chairman of the Association of Chief Police Officers and the head of the British Transport Police. It was ordered by Sir Paul Stephenson, the acting Commissioner of the Metropolitan Police and the officer who originally approved the arrest.

Sir Paul, who has applied to succeed Sir Ian Blair as Commissioner, said: "I am properly concerned about the issues being raised within the continuing debate surrounding the ongoing investigation into the leaking of government information."

Tensions are also growing between the police and the Crown Prosecution Service. Scotland Yard has suggested that the CPS sanctioned the decision to arrest Mr Green, which was denied by a CPS spokeswoman.

The war of words between the parties escalated last night as Ms Smith hit back at Mr Grieve's claims that she knew an MP was involved in the inquiry. She called his accusations "mischievous, perverse, inaccurate and wholly unfounded".