Defence secretary Ben Wallace warned Vladimir Putin’s subs are circling the coastline and claimed Russia was carrying out a ‘number of operations deliberately aimed at Britain’.
At least nine Russian vessels were spotted off the UK late last year, he added.
The situation was enough to prompt retired army officer Mr Wallace to brand Russia as Britain’s ‘number one adversary threat’.
Mr Wallace told the Telegraph: ‘We’re regularly visited by nosy Russian ships, and we are regularly visited now by a number of Russian warships.
‘We have tried de-escalation, we have tried methods but at the moment until Russia changes its attitude, it’s quite hard to see where we’re going to go. This is a country that killed someone in Salisbury.’
At least 150 Russian ships or submarines have been picked up by UK radar since 2013.
A Kilo-class sub was seen in the Irish Sea at the end of 2020, something the UK has not seen ‘for a very, very long time’, according to Mr Wallace.
The defence secretary’s comments were made during a trip to Portsmouth ahead of the deployment of the Royal Navy’s flagship HMS Queen Elizabeth on Saturday.
The mighty 65,000-tonne aircraft carrier has deployed on her maiden operational mission, a 26,000-mile voyage to the Far East and back.
Defence sources have warned that Russia submarines might try to spy on the £3.2bn flagship and her carrier strike group.
Mr Wallace said the deployment of HMS Queen Elizabeth was about projecting Britain’s ‘soft power’ and reaffirming alliances on the other side of the globe.
He added: ‘It is where hard and soft power meet, where the rubber hits the road. So, going to the Pacific shows that we can operate 8,000 miles away.
‘It shows that our friends like Japan – with common values, democracy, open economies – that we have that common link and that we can operate together, because the biggest strength is people who share our values. We have alliances and we have friends.’