Defence Secretary Ben Wallace has faced a call to reveal in Parliament how exactly the UK is responding to a Russian spy ship which has patrolled in the North Sea.
Lib Dem MP Jamie Stone raised concerns about sightings of the Admiral Vladimirsky in British waters.
While officially classified as an ocean research vessel, a joint investigation by European broadcasters says it is part of a fleet which is examining key energy sites for possible sabotage.
The ship is thought to have entered the Moray Firth last November, as part of a month-long journey across the Baltic Sea and North Sea.
Energy Voice says Mr Stone called for Mr Wallace to tell the Commons how the Government was responding to the incursions.
He said: “It is not a trawler, it is not a pleasure boat - it is a spy ship complete with armed guards.
Snooping around
“It has been snooping around the Beatrice oilfield and examining the interconnector to my constituency.
“It has been snooping around the oil stations in the North Sea and the oil pipelines.”
Mr Stone also referred to last year’s as-of-yet unexplained Nord Stream gas pipeline explosion, which is still subject to investigation but is believed to have been intentional.
He added: “We all know what happened in recent times in the Baltic with the gas pipeline.
“I do not take kindly to this happening and I regard this as a very important security issue.
“It affects the United Kingdom and our security in terms of energy.
Request for a statement
“What advice can you give me, Madam Deputy Speaker, in getting the Secretary of State for Defence to come to this place and make a statement in view of this urgent situation?”
Deputy speaker Dame Rosie Winterton replied that Mr Stone’s comments will have been heard and fed back to Mr Wallace.
- It emerged earlier this week that Britain is joining forces with the European Union to protect offshore wind farms and pipelines from Vladimir Putin in a new security pact.
The proposals include joint patrols using drones, as well as sharing information and intelligence to protect power supplies across the Continent from any possible sabotage by Russia.
Ursula von der Leyen, the European Commission’s President, warned that the bloc's critical infrastructure is “under threat”.
Speaking on the sidelines of the North Sea Summit with EU leaders in Ostend, Belgium on Monday, Grant Shapps, the UK Energy Secretary, said: “We are increasing international co-operation. We are reviewing measures, including drones.”
He added that Britain has “ramped up monitoring of the situation” to protect infrastructure.