Boris Johnson today vowed to 'hobble' the Russian economy with a 'massive' package of sanctions as he insisted the West 'will not look away' from the invasion of Ukraine.
In speech from Downing Street, the PM said Vladimir Putin cannot be allowed to 'snuff out' freedom in Ukraine with an act of 'wanton and reckless aggression.
He said Mr Putin had 'unleashed war' on the continent and the West must respond to ensure the eventual 'failure' of his offensive 'diplomatically, politically, economically, and eventually, militarily'. In a hard message to Germany and Italy among others, Mr Johnson also called for countries to wean themselves off gas and oil supplies from Moscow.
'Today, in concert with our allies we will agree a massive package of economic sanctions designed in time to hobble the Russian economy. And to that end, we must also collectively cease the dependence on Russian oil and gas that for too long has given Putin his grip on Western politics,' he said.
'Our mission is clear. Diplomatically, politically, economically, and eventually, militarily, this hideous and barbaric venture of Vladimir Putin must end in failure.'
During a round of interviews this morning, Mr Cleverly told Sky News: 'Ukraine is not part of Russia. The fantasy that President Putin is trying to play out – creating some kind of Tsarist expansionist Russia – absolutely has to be stopped.
He added: 'The military leaders around Vladimir Putin, they must know that this is a catastrophically bad judgment call by Vadimir Putin.
'Ukraine is a huge country physically. I have no doubt the Ukrainian people will be ferocious in defence of their homelands.
'The military leaders must know that this will come at a huge cost – not just to Ukrainians but to Russians.
'They are in a position, even if Vladimir Putin won't, they are in a position to stop this and we call on them to do so.'
Jailed Russian opposition leader Alexei Navalny said he was against Moscow's invasion of Ukraine as he stood trial from prison after President Vladimir Putin launched an attack.
'I am against this war,' Navalny was heard saying in a video of the in-prison trial published by independent news outlet Dozhd.
'This war between Russia and Ukraine was unleashed to cover up the theft from Russian citizens and divert their attention from problems that exist inside the country,' he said.
Wearing a prison uniform, Navalny said the war would 'lead to a huge number of victims, destroyed futures and the continuation of this line of impoverishment of the citizens of Russia.'
He is being tried inside the maximum security prison where he is held outside Moscow on fresh charges that could see his time behind bars extended by a decade.
His allies have said that the trial - which opened last week - has been purposefully timed to coincide with the Ukraine crisis.
Navalny has been behind bars for a year on old fraud charges, after surviving a poison attack he and the West blame on the Kremlin.