The Big Question: Will phone tapping convict more people, and why are its opponents so worried?

(BBC)

Why are we asking this now?

Because a government watchdog has warned against the use of phone-tap evidence in court, following mock trials in which its use gave every indication of being a disaster. Sir Paul Kennedy, the Interception of Communications Commissioner and a former Lord Justice of Appeal, said he could see no way to overcome problems with such evidence, and that the Government should drop its plans. Use of the technique at trials through March and April revealed "real legal and operational difficulties inherent in using intercept as evidence in the UK", he said, before adding: "I cannot see a way to safely overcome these". Aside from the immediate question of whether the law should be changed, intercepted phone calls have come under the spotlight with increasing frequency. Andy Coulson, the former News of the World editor who now advises David Cameron, revealed this week that he had his phone bugged during his reign at the paper. Last year Sadiq Khan, a Labour MP, had his phone bugged during conversations with a constituent who was suspected of involvement in terrorism.

What exactly is phone-tap evidence?

The permissibility or otherwise of tapping phones is an extremely sensitive subject. Proponents of the method's use argue that by allowing security and police officials to intercept private phone calls – which is relatively easy to do with technology that is already in operation – crucial evidence relating to criminal and terrorist intentions can be deduced, and thereby help secure more convictions. Campaigners also argue that it would reduce the need to impose control orders on suspects by enabling them to be tried instead. This could save the police hundreds of hours, they claim, and so speed up huge sections of the judicial system that are presently subject to terrible blockages.

What tapping takes place already?

Around 800 bodies are entitled to carry out several different forms of covert surveillance – phone taps among them – without breaching human rights laws. "Intrusive surveillance", such as planting bugs, tapping phone calls, and intercepting phone and internet data can only be deployed "to catch offenders suspected of serious crimes", and needs prior approval from a watchdog. Phone-tap evidence gathered abroad is allowed to be put before a jury already. Recordings from free-standing bugs are currently admissible in a criminal trial, and so too are recordings where one of the speakers is an undercover police officer.

What are the objections to using this method in court?

Traditionally, the case against use of phone-tap evidence in British courts has had two strands. First, civil libertarians object to any violation of a citizen's right not to be spied upon: the presumption at all times in a liberal society is that citizens should be able to go about their daily business without suspecting the Government's intrusion. And second, at the other end of the political spectrum, supporters of the security services suggest that public scrutiny of methods used by intelligence officials would reveal too much about their operations to potential terrorists. The objections to using phone-tap evidence in British courts have therefore created an unlikely political coalition.

Another argument, that phone- tap evidence will create too much paperwork, is widely considered to be bogus. There has also been extensive criticism of the system of control orders that allows intercept evidence to be heard behind closed doors, so that the defendant, who is represented by a special advocate, doesn't even know that they have had their phone tapped.

Hasn't this been rumbling on for ages?

It certainly has. Two years ago a Privy Council review into the use of phone-tap evidence, chaired by Sir John Chilcot (who will also chair the inquiry into the Iraq war), was launched by the Prime Minister. As expected, it reported that some way to use intercept material in court should be found, albeit with a number of key provisos. These include giving intelligence agencies the ability to veto use of their classified material and ensuring they only had to classify material deemed absolutely necessary. Another condition is that in trials defence lawyers should be banned from "fishing expeditions" in search of intercept evidence held by any agency.

Who's in favour of it?

Prime Minister Gordon Brown came off the fence early last year, saying that he supported the use of phone tap evidence in court. "The use of intercept evidence", the Prime Minister said, "characterises a central dilemma that we face as a free society" – and then he promptly set up a cross-party group to investigate the matter. Conservative leader David Cameron said that the use of phone tap evidence was imperative "so we [can] catch, convict, and imprison more terrorists". Liberal Democrat leader Nick Clegg has similarly added the support of his party to the campaign. Other prominent advocates include the former Attorney General, Lord Goldsmith, QC, and the former Director of Public Prosecutions, Sir Ken Macdonald, QC.

And who's against?

The Association of Chief Police Officers (ACPO) is opposed to allowing the deployment of such evidence because of its knock-on effect on counter-terrorism work and cases such as kidnappings. The Metropolitan Police and police in Scotland and Wales have the same view. MI5, MI6, and GCHQ have let it be known that they believe phone tap evidence would do "more harm than good" in the fight against organised crime and terrorism.

Where is the proof that phone tap evidence will actually work?

Proponents argue that phone tap evidence has been successfully introduced elsewhere, and that the experience of other countries radically strengthens their case. In America, tapes of incriminating comments made by mafia suspects during private phone calls are frequently played to them by the FBI after their arrest. The FBI consider such evidence indispensable to their work, and indeed senior American intelligence officials are said to be bemused by the lack of enthusiasm in Britain. It's not just them: Australia, Germany, Spain and Canada also use phone tap evidence.

What happens now?

The findings of the mock trial will come as a severe blow to the Prime Minister's plans, but are unlikely to cause him any political damage because the parties are united in their support. A Home Office spokesman said: "The issues surrounding Intercept As Evidence (IAE) are complex, sensitive and very important for national security and public protection. Given the complexity of the issues, the focus of work is to draw together the emerging conclusions, test their validity and to seek further advice on key points. It will only be following this work that ministers can make a final assessment whether IAE can be safely implemented." In other words, despite the latest setback, this episode will drag on interminably. The introduction of phone tap evidence is not likely to be a priority for the winners of the next general election, but this issue won't go away any time soon.

Will evidence gathered from telecoms surveillance be introduced in courts?

Yes...

* All the main political parties have said they are in favour of such evidence being used in trials.

* The Prime Minister has ordered reports into wiretap use despite objections from security services.

* Its continued use in several other countries will only make the proponents' case stronger.

No...

* Attempted use in mock trials has been a complete disaster.

* The coalition of objectors form a very powerful lobby and their co-operation may be needed for its effective use.

* Any change of government after a general election next year will push this down the priority list.