Boris Johnson suggested the invasion of Ukraine was motivated by Vladimir Putin’s fears about a revolution against his autocratic rule.
The Prime Minister said Mr Putin was in a “total panic” about the prospect of a popular uprising if freedom was allowed to flourish in Kyiv.
Mr Johnson said the war was a “turning point for the world”, forcing countries to stand up to Russia rather than “making accommodations with tyranny”.
Failure to support Ukraine now would result in a “new age of intimidation across eastern Europe from the Baltic to the Black Sea”.
In a speech at the Conservative Party spring conference in Blackpool, Mr Johnson said Mr Putin’s actions were not the result of concern about Nato – “he didn’t really believe that Ukraine was going to join Nato any time soon” – or the prospect of Western missiles being based there.
He also dismissed Mr Putin’s “crazy essay” about the historical unity of the people of the two countries as “semi-mystical guff” and “Nostradamus meets Russian Wikipedia”.
“I think he was frightened of Ukraine for an entirely different reason,” Mr Johnson said to an audience including Kyiv’s representative in the UK, Vadym Prystaiko.
“He was frightened of Ukraine because in Ukraine they have a free press and in Ukraine they have free elections.”
It is “precisely because Ukraine and Russia have been so historically close that he has been terrified of the effect of that Ukrainian model on him and on Russia”.
“He has been in a total panic about a so-called colour revolution in Moscow itself and that is why he is trying so brutally to snuff out the flame of freedom in Ukraine and that’s why it is so vital that he fails,” Mr Johnson said.
“A victorious Putin will not stop in Ukraine, and the end of freedom in Ukraine will mean the extinction of any hope of freedom in Georgia and then Moldova, it will mean the beginning of a new age of intimidation across eastern Europe from the Baltic to the Black Sea.”
Mr Johnson acknowledged there was little hope of an imminent change in Russian leadership.
“I don’t believe that democratic freedoms are going to sprout any time soon in the Kremlin, far from it.
“But with every day that passes I think that Putin becomes a more glaring advertisement for the system that he hates and despises, and it becomes ever more obvious why we have to stick up for Ukraine.”
In other developments:
– The Home Office said 8,600 visas had been issued under the Ukraine family scheme by 5pm on Friday.
– Ukraine’s ambassador to the UK Mr Prystaiko told the PA news agency that London-based consumer giant Unilever should close its operations in Russia.
– Former prime minister David Cameron was heading to Poland to deliver supplies to refugees fleeing the war in neighbouring Ukraine.
– His predecessor Gordon Brown called for a new international tribunal to be set up to prosecute Mr Putin and his allies.
Ukraine’s president Volodymyr Zelensky called on Mr Putin to hold face-to-face talks despite UK fears Moscow will use negotiations as a “smokescreen” to prepare for an even more brutal assault.
Mr Zelensky used a video message to say “it’s time to meet, time to talk” but, in the UK, Cabinet ministers urged caution about talks with the Putin regime.
Foreign Secretary Liz Truss said it was up to Mr Zelensky how his country approached peace talks but she was “very sceptical” about the Kremlin’s position.
She told The Times: “If a country is serious about negotiations, it doesn’t indiscriminately bomb civilians that day.”
Ms Truss said talks could be a “smokescreen” and “what we’ve seen is an attempt to create space for the Russians to regroup”.
Tory party chairman Oliver Dowden told Times Radio: “We of course have to treat the Russians with a high degree of scepticism given that they were the ones that commenced this war.”
He said the UK had to have a “hard-headed sceptical approach” but “if we can find a way through to a peaceful and negotiated settlement we should of course try to achieve that”.
In Ukraine, fighting continued on multiple fronts but 10 humanitarian corridors were established for aid and refugees – including one from the besieged port city of Mariupol and several around capital Kyiv.
British defence intelligence specialists believe Russia will wage a war of attrition, having failed in its goal of rapidly conquering its neighbour.
“This is likely to involve the indiscriminate use of firepower resulting in increased civilian casualties, destruction of Ukrainian infrastructure, and intensify the humanitarian crisis,” the Ministry of Defence said.