Former prime minister Liz Truss has called on the government to have a plan in place in case the Russian government under Vladimir Putin collapses.
It came as Foreign Secretary James Cleverly described the mutiny over the weekend as an “unprecedented challenge to President Putin’s authority”.
Speaking in the House of Commons, Ms Truss said: “We, and our allies – including the Ukrainians, including the Poles, including the Baltic states – need to make sure that we have a plan in the case of the implosion of Russia.”
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While he did not respond to Ms Truss’s point initially, Mr Cleverly later said that “the leadership of Russia is for the Russian people”.
“We do not speculate or attempt to predict – what we do is plan and put in place contingency arrangements,” he added.
“And so therefore, whatever the outcome of this conflict is, we shall be prepared.”
Mr Cleverly also said that “Prigozhin’s rebellion is an unprecedented challenge to President Putin’s authority – and it is clear that cracks are emerging in the Russian support for the war”.
The mutiny started on Friday evening, when the leader of the Wagner Group mercenaries, Yevgeny Prigozhin, called for an uprising against Russia’s military leadership.
Prigozhin and Wagner have been a notable part of the forces fighting on the Russian side of the invasion of Ukraine.
The mercenary forces began marching towards Moscow, taking the cities of Rostov-on-Don and Voronezh before stopping around 120 miles (193km) south of the capital on Saturday afternoon when the turmoil de-escalated.
Prigozhin is now set to be based in Belarus following negotiations with Putin, mediated through Belarusian leader Alexander Lukashenko.
UK Defence Secretary Ben Wallace echoed Mr Cleverly regarding the “internal” nature of the unrest in Russia.
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He said: “It was just another example of the cracks we have been seeing in public discourse where an anger amongst generals – I mean, I can’t remember how many generals have been fired or replaced by Russia and Russian leadership.
“If you remember early on, I think not a single one of the original sector or army commanders who started the invasion are still in place.
“I think they were all fired over this period.
“And then, of course, any army who suffers nearly 300,000 dead, or casualties, or desertions, cannot expect to get away with reputational damage and indeed friction among its leadership about why and how who’s telling the truth, who’s not.
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“And you know, Prigozhin just articulated that as a free agent.”
US President Joe Biden spoke shortly afterwards, and said it was important leaders gave Putin “no excuse” to blame the mutiny on the West, or on NATO.
“We made it clear we were not involved,” the president said. “We had nothing to do with it.
“This was part of a struggle within the Russian system.”