at common law, which has been held to reflect the Convention right to freedom of
expression in article 10.
19. It was held in Malone that it was not unlawful at common law to conduct telephone
interception. The requirement for authorisation was introduced by the 1985 Act, as
there was no pre-existing right at common law to complain of unauthorised
interception.
III. PROPORTIONALITY AND THE COMMON LAW.
20. The determination of the Tribunal on this point is that the principle of proportionality
does not apply to the review of the legality of interception of communications before 2
October 2000. The appropriate ground of judicial review of such conduct is that of
illegality or irrationality.
21.
It is common ground that, if a common law privacy right exists as a fundamental or
basic right so that the principle of legality applies, for example, to the Secretary of
State's power to issue interception warrants under s2 of the 1985 Act, interference with
the right must be necessary and the power to issue an interception warrant would not have
extended to the issue of a warrant which sanctioned a disproportionate interference
with the right.