Every PM since Harold Wilson may have reassured MPs and peers they were not being spied on, but many parliamentarians had suspicions to the contrary

Wilson doctrine was always just political rhetoric – now it's official

For almost 60 years, the Wilson doctrine has been regarded as a touchstone of British political life. MPs and members of the House of Lords were told repeatedly that they could sleep soundly in the knowledge that the UK’s intelligence agencies would never spy on their communications.

Every prime minister since Harold Wilson has uttered the same assurance; several home secretaries too – most recently Theresa May two days ago.

It fell to a government lawyer, James Eadie QC, to disclose the true position when a post-Snowden challenge was mounted before the investigatory powers tribunal (IPT). Each of these assurances had, he explained, been “a political statement in a political context, encompassing the ambiguity that is sometimes to be found in political statements”.

In other words, not necessarily true.

The doctrine’s genesis was a statement Wilson made to the Commons in November 1966, announcing that he had introduced the ban when he first entered Downing Street two years earlier. His purpose, however, had been not to reassure MPs, but to mischievously make clear that his Tory predecessor, Alec Douglas-Home, had had no such scruples.

Over the subsequent five decades, a number of MPs have had good reason to suspect they have been under surveillance by GCHQ or MI5.

Facebook Twitter Pinterest The former Tory MP Alan Clark wrote in his diaries that he was warned about ‘matters of personal conduct’. Photograph: Rex Features/Barry Phillips

They include the late Alan Clark, who was warned on his appointment as a junior minister in 1983, that the cabinet secretary possessed a file detailing “certain matters of personal conduct” that could expose him to blackmail. In his diaries, Clark concluded that these could have been gathered only through telephone intercepts.

Mike Hancock, the former Liberal Democrat MP for Portsmouth South, is said to have been convinced his phones were tapped at a time when MI5 was unsuccessfully attempting to have his Russian assistant deported on national security grounds.

GCHQ can monitor communications of MPs and peers, tribunal rules Read more

And then there are the MPs who know they have been under surveillance. They include not only Gerry Adams and Martin McGuinness of Sinn Féin – who no doubt expected to be bugged – but also Sadiq Khan, Labour’s candidate for the London mayoralty, whose conversations with an imprisoned constituent were found to have been recorded by police on behalf of MI5.

The government’s current position, as finally disclosed at the IPT, is that even if the Wilson doctrine had any real force, it could never have survived in an age of bulk data collection.

Whether this satisfies parliamentarians remains to be seen. Many prominent backbench Tories, such as David Davis, will be livid, while the Green politicians Caroline Lucas and Jenny Jones – who brought the case before the tribunal – are demanding the government legislates to provide specific protections for members of the Commons and the Lords.

“Our job is to hold the executive to account,” said Lady Jones. “In a democracy there is absolutely no excuse for people who contact parliamentarians to be subject to blanket surveillance by the security services.”