A legal challenge against the blanket surveillance of UK citizens today failed, following a landmark ruling by the Investigatory Powers Tribunal.
Green party politicians Caroline Lucas and Jenny Jones and former MP George Galloway jointly brought the case in order to challenge the blanket collection of citizens' electronic metadata under the "Tempora" programme, as revealed by Edward Snowden.
They believed that such blanket surveillance would breach the so-called 'Wilson Doctrine' implemented by Harold Wilson and subsequently upheld by successive prime ministers, including David Cameron.
The doctrine appeared to forbid the interception of MPs' communications. Just last week, home secretary Theresa May insisted the doctrine remained in force.
However, the Investigatory Powers Tribunal today ruled that MPs' communications with whistleblowers and their constituents have no special legal protection from state surveillance under the law, despite those long-held government doctrine apparently prohibiting it.
"The Wilson Doctrine has no legal effect," the tribunal ruled.
"MPs' communications with their constituents and others are protected, like those of every other person, by the statutory regime established by Part 1 of RIPA 2000"
The ruling was today condemned by those who brought the action.
"This judgement is a body blow for parliamentary democracy," Caroline Lucas said after the ruling.
"My constituents have a right to know that their communications with me aren't subject to blanket surveillance – yet this ruling suggests that they have no such protection,"
"As parliamentarians who often speak to whistle-blowers – from campaigners whose groups have been infiltrated by the police to those exposing corruption in government departments – this judgement is deeply worrying," Baroness Jones added
"Our job is to hold the executive to account, and to do that effectively it's crucial that people feel they can contact us without their communications being monitored.
"In a democracy there is absolutely no excuse for people who contact parliamentarians to be subject to blanket surveillance by the security services."
Lawyers said the ruling meant MPs had been living under an "illusion" that their communications were private.
"Today's judgment has shredded the Wilson Doctrine," solicitor Rosa Curling from Leigh Day said.
"Democratically elected MPs, who for the past half century have relied upon this illusion of trust from the security services, can now be spied on legitimately by the security services.
"Members of the public can no longer be assured that their correspondence with their elected representatives, either to raise complaints about government policies or whistle-blow and expose wrongdoings of the government, will not be monitored or snooped on by the government and its agencies."