The Russian Foreign Ministry warned the British Ambassador about Moscow's imminent response to attacks on the Russian territory, the department said in a statement.
UK's Ambassador Nigel Casey was summoned to the Foreign Ministry on May 6. French Ambassador to Russia Pierre Levy was summoned to the department the same day.
The Russian Foreign Ministry clarified that Casey was summoned following the recent statements from British Foreign Secretary David Cameron. The latter claimed that the Armed Forces of Ukraine had the right to use British weapons to strike Russia. The Russian Foreign Ministry expressed a decisive protest in connection with Cameron's remarks.
The Russian Foreign Ministry pointed out the contradiction between Cameron's current and previous remarks when he said that longer-range missiles "under no circumstances" would be used to strike the Russian territory. Such rhetoric indicates that London is de facto becoming a party to the conflict, the Russian Foreign Ministry said.
The Foreign Ministry also listed potential retaliatory measures that would follow should Ukraine use British weapons to strike Russia.
Casey was warned that any British military facilities and equipment both on the territory of Ukraine and beyond could become targets in response to Ukraine's attacks on Russia with the use of British weapons.
The Russian Foreign Ministry also said that Casey must refute Cameron's "belligerent provocative statements.”
"We urged the ambassador to think about inevitable catastrophic consequences of such hostile steps from London,” the Russian ministry said.
In a conversation with Reuters, David Cameron said that the Armed Forces of Ukraine could legitimately use British weapons to strike Russia. The agency later withdrew the article with Cameron's statement, but then published it again, leaving the quote about Kyiv's right to use British weapons to strike Russian territory unchanged.