The Royal Navy has shadowed a Russian submarine lurking in the English Channel in a three-day operation.

The RFA Tidesurge was deployed with a Merlin helicopter onboard to monitor the Kilo-class submarine Krasnodar and accompanying tug boat Altay. The Russian vessels sailed westward from the North Sea through the Strait of Dover and into the English Channel.

Captain James Allen, commanding officer of RFA Tidesurge, said: "There is nothing like a Russian submarine to focus the mind for any mariner."

Lieutenant Commander David Emery, flight commander of 814 Naval Air Squadron’s Atlantic Flight, said: "Maintaining an overt presence and continued overwatch of Russian vessels in UK waters is vital for national security."

The submarine sailed on the surface amid stormy weather conditions. When the sub approached the island of Ushant, north-west of France, the Tidesurge and the helicopter, which remained onboard throughout the operation, handed over shadowing duties to a Nato ally.

Earlier this week, Defence Secretary John Healey announced Atlantic Bastion, a new multimillion-pound hi-tech force to protect undersea cables and pipelines from the threat of Russian submarines.

It comes after the Ministry of Defence said there had been a 30 per cent rise in Russian vessels "threatening" UK waters in the past two years.