Apologise for police raid on MP 'or you're toast', Speaker told

Tory and Lib-Dem grandees were today set to challenge the Speaker if he refuses to allow a proper debate on the decision to let detectives search shadow immigration minister Damian Green's Commons room.

But backbench MP Richard Bacon, who is rallying support to challenge the Speaker's authority, issued a blunt warning to him.

Mr Bacon, who sits on the all-party Commons public accounts committee, had sought a meeting with Mr Martin. He managed to speak only to his secretary Angus Sinclair but left him in no doubt about the anger among MPs over the affair.

"He needs to say sorry, it should not have happened, I take responsibility and it won't happen again," the Conservative MP said he told Mr Sinclair.

"If he says anything less than that I think he's almost certainly toast and he may be toast anyway."

The row intensified as Lord Mandelson stepped up Labour attacks on the Tories over the affair, accusing the party of using the row with the Speaker as a "smokescreen" to hide its own role in breaking the law. "Whilst I recognise the anger being expressed by some MPs is no doubt sincerely expressed by some of them, I also think it is particularly self-serving of Conservative MPs who want to put up a smokescreen to hide their own party's relationship in allegedly colluding with a Home Office official in breaking the law," he said.

However, the embattled Speaker faced renewed pressure today after a former chief prosecutor tore holes in the police inquiry into Mr Green.

The scathing criticism from Sir Ken Macdonald, who stood down as director of public prosecutions just weeks ago, raised further questions over Mr Martin's conduct.

The Speaker has bowed to demands for a debate on the row, according to his ally Lord Foulkes, although he said this had been a government decision which will inevitably reinforce the belief that ministers have too much influence over Mr Martin.

Speaking on BBC2's Newsnight, Sir Ken raised serious doubts over whether any convictions would result from the leak investigation.

He also suggested the Metropolitan Police had blundered by failing to properly consult with the Crown Prosecution Service. "If the police proceed in a case which is this sensitive without consulting prosecutors, then things will go wrong," he told the programme.

Tories upped their attack over Mr Green's treatment by releasing footage of police arriving to carry out the raid. Many MPs believe officers were allowed in on a "fishing trip" to seek information from Mr Green's office after civil servant Christopher Galley, 26, who is accused of passing him sensitive Home Office documents, was arrested and bailed earlier this month.

Lord Foulkes spoke out on BBC Radio 4's Today programme in defence of Mr Martin, adding: "The Government has agreed to a debate. I think it's going to take place as the first debate in the Queen's Speech."

Mr Martin was due to make a statement to MPs on the affair at 2.30pm today. The Met announced yesterday that British Transport Police head Ian Johnston was to carry out a review of the probe and the arrest of Mr Green last Thursday.

Meanwhile, Home Secretary Jacqui Smith lashed out at the Tories for lacking "respect" for the law.

She dismissed suggestions that she was not being straight over what she knew about the investigation before Mr Green's arrest.