Russian President Vladimir Putin would see the UK breaking away from the EU as a sign of Britain's weakness, according to Hilary Benn. The shadow foreign secretary issued the warning during a pro-EU speech at the Chatham House think tank on 11 February.
The top Labour MP claimed the economic sanctions imposed on Russia over its involvement in the Ukrainian civil war are "clearly biting" and a Brexit would undermine the EU's "collective strength" in facing up to Moscow.
"The situation remains unstable, however, and the Minsk agreement has yet to be fully implemented. But it is precisely because of Europe's collective response that we have been able to exert real pressure and have an impact," Benn told the London audience. "And efforts towards the creation of an EU-wide energy union will, over time, weaken Russia's dominance as an energy supplier in Europe.
"Let's be clear, President Putin would shed no tears if Britain left the European Union. He would see Brexit as a sign of our weakness and of the weakness of European solidarity at the very moment when we need to maintain our collective strength."
The comments come after both sides of the EU referendum debate have accused each other of "scaremongering". Liberal Democrat leader Tim Farron has admitted that fellow pro-EU politicians have engaged in "a nasty race to the bottom".
Benn has been at the centre of a bitter row at the top of the Labour Party over Britain's nuclear deterrent, Trident. Jeremy Corbyn and his new shadow defence secretary, Emily Thornberry, are against renewing the weapons system.
But Benn, who also defied the Labour leader by supporting a UK bombing campaign in Syria, is a supporter of Trident. When pressed on the issue after his speech, he queried: "Who fancies living in a world where everyone else has given up their nuclear weapons but North Korea still has theirs?"
David Cameron is yet to set a date for the EU referendum as he wraps up is renegotiation with Brussels but 23 June has been mooted in the press for the ballot. Benn admitted Labour would back staying in the 28-nation bloc regardless of what reforms the prime minister can secure.
It seems the British electorate are not as certain as the Labour frontbencher. The latest opinion poll from YouGov for The Times, of more than 1,600 people between 3 and 4 February, put the "leave" vote nine points ahead of "remain", at 45% versus 36% respectively.