Russia’s hybrid warfare could push Nato to trigger its mutual defence clause, according to the head of Germany’s foreign intelligence service.

Moscow is not in direct conflict with the West right now but that could change if Russia continues its acts of sabotage.

Bundesnachrichtendienst chief Bruno Kahl said in Berlin on Wednesday: “The extensive use of hybrid measures by Russia increases the risk that Nato will eventually consider invoking its Article 5 mutual defence clause.”

Nato’s Article 5 is a cornerstone of the treaty all member states sign up to.

It means that if a Nato ally is the victim of an armed attack, every other member will consider this as an offensive act against its own state – and respond accordingly.

Kahl added: “We don’t have any indication yet that Russia intends to go to war [with the west], but if such sentiment gains the upper hand in the government in Moscow, then the risk for a military confrontation will grow over the coming years.”

Putin has threatened to bomb the UK after Downing Street gave Ukraine permission to use its long-range missiles against targets inside Russia.

Security forces across the west, including Nato, have warned for months that Russia is already launching cyber attacks on Ukraine’s allies – although Moscow has denied it.

There is also growing speculation that Moscow is ready to strike out at the UK through cyber strikes and fake news.

MI5 chief Ken McCallum warned last month that Putin’s “henchmen” want to cause “sustained mayhem on British and European streets”.

Former defence minister Tobias Ellwood went even further and told the i newspaper that the UK already at war with Putin.

He said: “Full-on state-on-state warfare is costly, unpredictable, and unpopular – just look at the mess Putin has made for himself in Ukraine.

“But that hasn’t stopped Moscow from attacking Britain and other countries in subtler, harder-to-pin-down ways.

“Welcome to grey zone warfare, where Russia uses cyber attacks, disinformation, and covert operations to weaken its enemies – all without formally declaring war. It’s clever, deniable, and devastating.”

Kahl also told his audience in Berlin that, by the end of the decade, Moscow will be strong enough to attack Nato.

He said: “The increasing ramp up of the Russian military potential means a direct military confrontation with NATO becomes one possible option for the Kremlin.”

The intelligence chief claimed Russia would only attack any Nato state to test the red lines set by the west and break down unity between states.

He said: “In Russia’s view, this goal would be reached if Article 5 were to remain effect in case of a Russian attack.”