Legal professional bodies have renewed their call for statutory protection for professional privilege despite a landmark ruling against the security services.

The Investigatory Powers Tribunal (IPT) this week ordered intelligence agency GCHQ to destroy illegally intercepted communications between Libyans subjected to renditions and their lawyers in the UK. This is believed to be the first time the tribunal has ordered an intelligence agency to give up surveillance material in its 15-year history. 

However, both the Law Society and the bar said the ruling did not go far enough to protect lawyer-client communications.

Andrew Caplen, president of the Law Society - which intervened in the case - said: 'The current legislative framework remains unsuitable and we hope that the Regulation of Investigatory Powers Act will be amended or replaced to include explicit protection of legal professional privilege.'

Bar chairman Alistair MacDonald QC said: 'Though it is encouraging that the IPT found that in this particular case communications were unlawfully intercepted as a direct result of the inadequate policies relating to [privileged] material, there remains a major concern about the wider implications of the tribunal's decision not to give injunctive relief. The law has always recognised that a lawyer-client communication only loses its privilege where it is made for a criminal purpose.'

He described as 'deeply troubling' the government's argument that there are wider exceptions to privilege than this. 'We hope that future governments - of whatever stripe - will not be tempted to advance this dangerous argument again.'

Even when promised new codes and policies are put in place, they will not be robust enough, he said. Legal privilege 'needs proper parliamentary and judicial oversight to be sufficiently protected'.

The case arose from civil claims against a former foreign secretary, Jack Straw, former MI6 counter-terror head Sir Mark Allen, and the UK government for their role in the rendition of opponents of the former Libyan dictator Colonel Gaddafi.

The first claim was settled in December 2012 for £2.2m; the second claim comes before the Supreme Court this year.