An armed rebellion led by a paramilitary organisation has been named "the most significant challenge to the Russian state" in recent years, according to UK defence officials.
Yevgeny Prigozhin, chief of the Wagner mercenary group, has vowed to take down Moscow's military leadership, with Vladimir Putin branding the actions of the private military company a "betrayal".
In its latest intelligence briefing, the Ministry of Defence (MoD) said that "over the coming hours, the loyalty of Russia's security forces... will be key to how the crisis plays out" as Wagner forces appear to be making their way towards the Russian capital.
