A privy council report published in late January recommended in principle that the ban on intercept evidence in court be removed. This is fast becoming the consensus view. While there are some strong arguments for its removal, the devil is going to be in the detail of how it is done.
The police and other intelligence agencies can be authorised to conduct surveillance activities under the Regulation of Investigatory Powers Act 2000. Evidence from bugging—the use of concealed listening devices or cameras—is admissible in court. But intercept evidence—which covers the covert interception of telephone calls, faxes, email and ordinary post—is not. So while a phone conversation bugged by an external listening device may be admissible, the same information gained by intercepting or "tapping" the call would not be. Intercept evidence therefore has a value in the detection and surveillance of crime, but not its prosecution.
It is difficult to find arguments in favour of the ban from geography or history. Several countries use intercept evidence in criminal proceedings, and for centuries it was admissible in English criminal trials—the ban on its use in court was introduced only in 1985. Intercept evidence was used in the treason trial of Mary, Queen of Scots in 1586 (Elizabeth I's spymaster intercepted letters implicating her knowledge of the Babington plot). Fifty years ago, the privy council concluded that, while it was rarely used in criminal proceedings, intercept evidence was still admissible.
The ban was brought in by parliament following an adverse ruling by the European court of human rights. But the same court has also acknowledged that states can, in principle, use intercept evidence in criminal cases. Human rights reasons alone do not appear enough to justify keeping the ban.
It has been argued that removing an intercept ban in court cases may affect relations between the security services and the police. Agents could be compromised. But the prosecution need not proceed with cases where such compromising evidence may appear. It can also withdraw the case later if this becomes an issue.
Countermeasures from criminals might escalate, it has been argued. But sophisticated criminals presumably have some idea they might be wiretapped and take precautions in the way they communicate information. It is therefore doubtful whether the knowledge that what they are saying, if intercepted, may be usable in court would make much difference.
Ultimately, the real problem with implementing the removal of the ban may be in the application of the legal principle of public interest immunity (PII). The prosecution is normally required to disclose relevant evidence to the defendant in criminal proceedings. But under PII principles, the court can restrict disclosure of evidence to the defendant where there is a countervailing public interest. Intercept evidence would be a regular candidate in that category, where defendants might seek to challenge the basis of the intercept by seeking further sensitive satellite material, only to find the challenge blocked by PII.
The full extent of intercept material requested by the defendant may, if ordered by the court to be disclosed, be lengthy, possibly require translation and be expensive. But economic considerations are less perhaps the concern of the court than the intelligence services and the government.
To make removing the ban on intercept evidence work, the challenge will be to legislate on the application of PII in this context. Judges want to ensure that trials are fair and the government wants to secure anti-terror convictions, while ensuring that Britain does not fall foul of the European convention on human rights. It is likely that test cases on any reform would swiftly find their way to Strasbourg. For these reasons, there may be challenging times ahead before the intercept ban can be abolished on a sound basis, even if many agree that it should be.
