Russia’s embassy in London has threatened the West with nuclear war if it attacks the Kremlin’s European outpost of Kaliningrad.

The warning was issued on the embassy’s social media channels in response to a TV show, aired last week, which saw major figures including Michael Gove, Dame Penny Mordaunt and former UK ambassador to the US Kim Darroch act through a fictional scenario in which Russia attacks the UK.

During the show, Sky’s The Wargame, the prime minister played by Gove orders a retaliatory attack against Murmansk and Kaliningrad.

In a scathing post to its Telegram channel, the Russian Embassy in London warned: ‘Those advocating plans to blockade or strike Kaliningrad should have no illusions about the consequences.

‘Any British or NATO military action against Russian territory would be met with a response using all means at Russia’s disposal, including nuclear weapons.

Murmansk is a vitally strategic part of Russia’s mainland, home to the nation’s Northern Fleet.

Kaliningrad is a Russian exclave between Nato members Poland and Lithuania that has been touted as a possible launch location for the Kremlin’s nuclear missiles.

The embassy added: ‘Russia has repeatedly made clear that it neither seeks confrontation with NATO and Europe nor intends to attack them. But should anyone choose to unleash such a conflict, they must be under no illusion that Russia will respond accordingly.’

The embassy’s post also referenced a piece written in the i Paper, which described Kaliningrad as Vladimir Putin’s ‘greatest weakness’.

One former Nato official said: ‘Russia knows it’s a vulnerability.’ A security analyst called it ‘the Achilles Heel of the Russian Federation’.

But experts also point to the region as being a possible weakness for Nato.

Yesterday, it emerged that Lithuania and Poland are developing evacuation plans in the event of full-blown war with Russia.

The countries are preparing procedures, logistics and infrastructure, including evacuation routes for civilians, through the Suwalki Gap, the 60-mile strip of border between Poland and Lithuania, where Nato generals fear Putin might stage an attack.

The corridor connects Belarus, a Moscow ally, to the Russian enclave of Kaliningrad.

If Putin deploys his forces from Belarus across the gap to Kaliningrad, he could isolate Estonia, Latvia and Lithuania from allies in central and western Europe.

Vilnius and Warsaw are developing a bilateral agreement to provide a framework for the plans, according to the Lithuanian National Crisis Management Centre.

The announcement came as Lithuania launched nationwide drills, including practice evacuation procedures at its border with Poland.

Moscow has increasingly been testing Nato’s resolve through its campaign of covert attacks on bordering countries.

Vilmantas Vitkauskas, the head of Lithuania’s National Crisis Management Centre, said: ‘Procedures, logistics, and infrastructure capabilities are being analysed together with colleagues from Poland, and the plan itself should be developed once an agreement is reached between the two countries.’

The plans will also account for the evacuation of civilians in Estonia, Latvia and Lithuania, he added.

In the event of a threat at the border, border controls are being considered, to ensure mobilisation and to ‘prevent people in certain key roles from leaving the country’.

Some 20 Polish officials were dispatched to Lithuania to participate in exercises testing border procedures, while about 3,000 officials and 1,000 volunteers are taking part in drills, which will run until October 2.

Earlier this month, Polish prime minister Donald Tusk warned that intelligence assessments show Russian ‘plans for hybrid strikes using drones and missiles against countries supporting Ukraine, including Poland’.

He described the ‘provocations’ as being ‘far more dangerous than those we have faced so far’.

Russia is suspected of being responsible for covert attacks on several sites in Nato countries, including a warehouse in Britain, a weapons factory in Estonia and an airport in Germany.