Gordon Brown will announce the findings of an independent review today that will open the door to the use of intercept evidence in court.

A cross-party group of four Privy Counsellors has concluded that, in principle, bugged conversations and e-mails should be revealed to juries, The Times has learnt. The group’s report emphasises that evidence should be released only where it does not disclose details of secret eavesdropping techniques or place too heavy an administrative burden on the police, security and intelligence services or GCHQ.

Nevertheless, it represents a victory for those like Sir Ken Macdonald, the Director of Public Prosecutions, who argue that intercept evidence will help to secure convictions in terrorist trials. David Davis, the Shadow Home Secretary, and Nick Clegg, the leader of the Liberal Democrats, support allowing wire-tap evidence in court.

Mr Brown will announce the results of the review, led by Sir John Chilcott, in a Commons statement today. He is also expected to renew his call for cross-party co-operation on new counter-terrorism measures.

In clearing the way for the admissibility of wire-tap evidence Mr Brown hopes to win more support for the Government’s proposals to extend the maximum period of detention without charge from 28 to 42 days.

He does, however, risk a confrontation with MI5, MI6 and GCHQ, which have, until now, fought demands that they make available to the courts material collected during bugging operations.

The Prime Minister asked Sir John, a former permanent secretary at the Northern Ireland Office, to conduct a review within a month of entering No 10 last summer. The four Privy Counsellors took evidence from Britain’s leading intelligence and legal figures and spoke to authorities in other countries before reaching their conclusion. It is thought that they will present two reports tomorrow, one a public report and the other a confidential document dealing with issues such as GCHQ’s ability to eavesdrop on new communications technology such as voice calls over the internet.

A Whitehall source said: “There is still a long way to go. There is a lot more work that needs to be done.”

Mr Brown will also face questions today on why his ministers were apparently not told that the Labour MP Sadiq Khan was twice bugged by the police when he visited Babar Ahmad at Woodhill prison in 2005 and 2006.

In an astonishing twist last night it emerged that officials at Jack Straw’s Justice Department received a press inquiry on December 14 relating to Mr Khan’s visits to the prison, which included the allegation that the meetings were bugged. Officials told Mr Straw only about the concerns over Mr Khan’s visits, however, and did not inform him of the allegation that the MP’s meetings with Mr Ahmad were bugged. The Times understands that Mark Davies, Mr Straw’s special adviser, was among those who were told of the press inquiry about bugging but did not pass it on to Mr Straw. The Justice Secretary has insisted that the first he knew of the bugging was on Saturday, when he was told about the news story in The Sunday Times.

He is considering whether to extend an official inquiry into the bugging of an MP to cover revelations in The Times that recordings were made of a lawyer’s conversations with his client in prison.

The Ministry of Justice said last night that Mr Straw was taking detailed advice on the disclosure that illegal recordings were made of telephone calls between the solicitor Simon Creighton and his client, Harry Roberts, a convicted murderer.

A ministry spokesman said that Mr Straw would listen to the Prison Service and the Treasury Solicitors before deciding whether to broaden the inquiry into the surveillance operation involving Sadiq Khan MP and Mr Ahmad, who is fighting extradition to the United States.

David Davis, the Shadow Home Secretary, urged Mr Straw to begin a fresh inquiry by Sir Christopher Rose, the Surveillance Commissioner, into the Roberts case. He said: “As soon as this original inquiry is over in the next two weeks \ given the serious concerns over the rights of privacy between lawyers and their clients, Sir Christopher should launch a second-stage inquiry into the alleged breaches of privacy.”

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