The Wilson doctrine, which protects politicians phones and communications from tapping, initially applied to the Scottish Parliament – but new guidelines indicate this is no longer the case.
In a letter to David Cameron, the First Minister called for confirmation that the intelligence agencies would treat MSPs in the same way as Westminster members.
She also pointed out that the Scottish Government was not consulted on changes to the Wilson doctrine.
Ms Sturgeon states: “Excepting truly exceptional circumstances involving national security, the confidentiality of communications between parliamentarians and their constituents is of the utmost importance.
“I am sure you will also agree that it is just as important for MSPs as it is for MPs. This principle of confidentiality is what the ‘Wilson doctrine’ was introduced to protect.”
The First Minister also demands to know whether any MSPs’ communications have been intercepted and if ministers knew about the decision to change the Wilson doctrine so that it no longer covers Holyrood.
She also asks for an “immediate assurance” that the policy change by Government Communications Headquarters (GCHQ) will be reversed and that the Wilson doctrine will again be applied to MSP communications.
The change emerged at a meeting of the Investigatory Powers committee which is meeting in London this week.Lawyers Ben Jaffey and Jude Bunting told a newspaper: “All protection for devolved legislators has been removed.”
The lawyers are representing Green Party politicians Caroline Lucas and Lady Jones, who claim disclosures by whistleblower Edward Snowden made it clear GCHQ was capturing their communications, in breach of the Wilson doctrine.
Scottish Parliament Presiding Officer Tricia Marwick has also written to Mr Cameron seeking clarification.
Her letter said: “I feel strongly that all elected members should be treated in the same way, regardless of which parliament or assembly they are elected to, especially with regard to any communications a member has with his or her constituents.
Labour’s acting Scottish leader Iain Gray said: “This is outrageous. It is utterly unacceptable for the communications between devolved representatives across the UK and their constituents to be monitored by GCHQ.
“There needs to be full transparency from the UK government on this. We need to know urgently who decided on this major rule change and when. For the rules on spying on elected representatives across the UK to change without any sort of public scrutiny or accountability is a democratic outrage.”
Scottish Labour MP Ian Murray has tabled a series of parliamentary questions in the Commons in response to the report.
The convention is named after former prime minister Harold Wilson, who pledged in 1966 that MPs’ and peers’ phones would not be tapped.
In December 1997, then prime minister Tony Blair said it extended to electronic communication, including e-mails.
However, the policy was never officially extended to cover the devolved parliaments in Scotland, Wales and Northern Ireland once they were set up in 1999. And while GCHQ voluntarily treated MSPs in the same way as MPs until March this year, that now appears to have been changed.