It has been claimed that an MP has had been bugged by police. Here is a guide to the issue:
What is alleged to have happened?
Counter-terrorism officers are said to have secretly recorded two conversations between Labour MP Sadiq Khan and Babar Ahmad, a constituent and childhood friend, who is in Woodhill Prison, Milton Keynes, awaiting deportation to the US. Mr Ahmad is accused there of running websites supporting the Taleban and Chechen terrorists, though he faces no charges in the UK. Mr Khan has campaigned for Mr Ahmad's release.
Surely they were bugging the terror suspect not the MP?
According to the Sunday Times, the bugging device was hidden inside a hollowed-out table in the jail's main visiting hall. Potentially it could record anyone visiting the jail, although the target was the prisoner, not the visitor. The paper says it has seen a document showing there were internal concerns about bugging the MP, who is also a lawyer, but it went ahead anyway.
What was wrong with that?
MPs are afforded special protection from bugging under the Wilson Doctrine.
The Wilson Doctrine? What's that?
This was first introduced in 1966 under the then prime minister Harold Wilson to assuage concerns that MI5 might be monitoring politicians with no oversight or authorisation. Mr Wilson gave an undertaking there would be no tapping of MPs' phones. This was later widened to include all forms of communication and to include peers in the House of Lords. The doctrine has been confirmed by subsequent prime ministers.
Even Gordon Brown?
Not entirely. In a little noticed reply to a written question last year Mr Brown backed the idea of the Wilson doctrine but, crucially, said that it only applied to cases where a minister had to give the go ahead for an operation.
Who gives the go ahead for what?
If any of the intelligence services want to intercept communications or plant a bug, they require authorisation from a minister. However, if the police wish to carry out surveillance - such as the use of covert recording devices in a prison as alleged in this case - such a move can be taken with the permission of a chief constable or officer of equivalent rank and without ministerial approval.
What are the rules for bugging you or me?
According to Sir Paul Kennedy, the Interception of Communications Commissioner, 600 public bodies can now request covert access to the communications records of the entire population.
How commonplace is it for people to be bugged?
In his annual report for 2006, Sir Paul found that the majority of requests related to the supply of communications data - telephone calls, emails and post - rather than actual bugging of phone conversations. This means that information held about a person by phone companies and internet providers can be accessed to reveal their network of friends and colleagues, how often and when they are communicated with and where the person has been when the communication has taken place. Of 253,557 applications to intercept private communications under surveillance laws in the last nine months of 2006, it is understood most were approved.
Who can bug people and for what?
Police and intelligence services can intercept and bug people's phone calls, emails and letters. But hundreds of public bodies can now ask for permission for covert access to people's communications records. Local councils can also request such powers to tackle matters such as suspected fly-tippers. In all cases it is not necessary to be seeking to detect crime. It can also be to eliminate suspects, trace witnesses or for things like investigating air or rail accidents.
Why should MPs be treated differently?
Tradition dictates that Parliament is sovereign and therefore MPs should not be subject to the police and courts. However, Sir Paul believes MPs should not enjoy any special protection from being bugged. He has also denounced the Wilson Doctrine, as "totally indefensible". Sir Paul's predecessor, Sir Swinton Thomas, told ex-prime minister Tony Blair it undermined the constitution and was kept in place purely in the "self interest" of MPs.
Who knew what, when about the MP bugging?
Officials in the Home Office and Ministry of Justice were told in December of the incident. Shadow home secretary David Davis says he sent a letter to Prime Minister Gordon Brown that month alerting him to the possible breach of the Wilson Doctrine. However, Downing Street says it has no record of the letter being received by Mr Brown, despite "a detailed check" and the prime minister knew nothing about it. Justice Secretary Jack Straw and Home Secretary Jacqui Smith say they did not know about the allegations until the Sunday Times reports emerged at the weekend.
What happens next?
Sir Christopher Rose, the chief surveillance commissioner, has been asked by Jack Straw to conduct an inquiry to establish the facts of what happened. He has said he will seek to deliver his report to ministers by 18 February.