A former head of MI5 has said Britain may already be at war with Russia.

Baroness Manningham-Buller, who led the Security Service between 2002 and 2007, cited cyberattacks, espionage and covert operations on British soil as evidence for her claim.

Lady Manningham-Buller said she was inclined to agree with Fiona Hill, a foreign policy specialist and former adviser to Donald Trump, who has said previously that Britain is already at war with Russia.

She told the Lord Speaker’s Corner podcast: “Fiona Hill may be right in saying we’re already at war with Russia.

“It’s a different sort of war, but the hostility, the cyberattacks, the physical attacks, intelligence work is extensive.”

Lady Manningham-Buller said Vladimir Putin had moved to a position of sustained hostility to the West since the invasion of Ukraine three years ago and was engaging in sabotage and intelligence collection, as well as attacking people in Britain.

She also suggested previous governments were wrong to believe Russia could join the club of Western democracies.

Speaking of her meeting with Mr Putin in 2005, Lady Manningham-Buller said: “We all hoped that at the end of the Soviet Union we would have a potential partner. That was one of the reasons why Putin was with us for the G8 summit in 2005.

“I met him when he came back to London. But actually we were wrong because Russia is extremely hostile to the West. I didn’t anticipate that within a year he’d be ordering the murder on London streets of Alexander Litvinenko.”

Mr Litvinenko, a former agent of Russia’s spy agency the FSB, was poisoned in London in 2006.

In 1998, he said he had been ordered to kill Russian businessman Boris Berezovsky, which led to him being persecuted by the Russian authorities and fleeing to Britain in 2000.

An inquiry found he was murdered by Russian agents, probably with Putin’s approval.