The Ashford MP Damian Green has spoken out about his arrest and defended his involvement in leaking information from the Home Office.

The MP made his first public comments since just after his release during a debate in the House of Commons on Thursday. He was responding to a statement made by Speaker Michael Martin earlier on.

Mr Green said he was grateful for the support of MPs on all sides of the House after his arrest last Thursday.

"Can I make it absolutely clear that I do not believe that MPs are above the law? Those who have the real power in this country - ministers, senior civil servants and the police - are also not above the law.

"An MP endangering national security would be a disgrace but an MP exposing embarrassing facts about Home Office policy is simply doing his job in the public interest."

He went on to say it would be "a bad day for democracy" if members of parliament were prevented from exposing facts that ministers would prefer to keep hidden.

In his statement, the Speaker revealed police had not had a warrant when they searched Mr Green’s parliamentary office. He also announced an inquiry into the affair.

Michael Howard, the Folkestone and Hythe MP and former Home Secretary, who also spoke, said the investigation had been a deplorable affair and caused outrage in the House of Commons.

He sought assurances that MPs who wanted to question the involvement of ministers in the investigation during a debate scheduled for Monday would be allowed to do so.

"Will you [the Speaker] make it clear that it will be free for any member who takes part in the debate to question the conduct of ministers and civil servants?"

The arrest of Mr Green and the removal of computer equipment from his homes had affected his ability to do the job - "namely to represent his constituents and hold the Government to account".

Earlier, the acting head of the Metropolitan Police Sir Paul Stephenson rejected claims that the Met Police came under any influence from ministers during its investigation into Home Office leaks.

Speaking at a meeting at City Hall, the Mayor of London’s HQ, Sir Paul revealed the Crown Prosecution Service had now been handed a file about the police investigation.

Answering questions about the arrest of Mr Green, who denies any wrong-doing, he said:

“Officers have an obligation to locate and secure evidence to avoid any circumstances where potential evidence could be lost. With this in mind, the decision was taken to arrest and search the relevant addresses in accordance with the police and criminal evidence act."

He added: "I would strongly refute that I or any senior officer under my command have, or would allow, any improper influence of our operational judgement and actions for political purposes. That is not what we do"