Vladimir Putin's advisers are scared to tell him the truth about the progress of his Ukraine invasion, the head of the UK's GCHQ spy agency has said.
Sir Jeremy Fleming said Russian troops are even "refusing to carry out orders, sabotaging their own equipment and even accidentally shooting down their own aircraft".
In a rare public address during a visit to Australia, Sir Jeremy said Mr Putin had "massively misjudged the situation" and the extent of the Russian leader's "misjudgements" must be "crystal clear to the regime".
"We've seen Russian soldiers – short of weapons and morale – refusing to carry out orders, sabotaging their own equipment and even accidentally shooting down their own aircraft," he said.
"It's clear he misjudged the resistance of the Ukrainian people," he said. "He underestimated the strength of the coalition his actions would galvanise.
"He under-played the economic consequences of the sanctions regime. He overestimated the abilities of his military to secure a rapid victory.
Watch: Time to double down on military defensive aid to Ukraine and Russian sanctions, PM says.
"It's become his personal war, with the cost being paid by innocent people in Ukraine and increasingly, by ordinary Russians too," he added.
Sir Jeremy also said western allies were making "deeply secret intelligence" public to get ahead of Mr Putin's information war, while also tackling cyber threats.
He also warned China not to become "too closely aligned" with the Kremlin and said the country's long-term interests are not well served by an alliance with a leader that "wilfully and illegally" ignores the international "rules of the road".
His intervention comes after Prime Minister Boris Johnson last week directly confronted President Xi Jinping over Beijing's stance on the conflict in Ukraine.
And Foreign Secretary Liz Truss will urge Indian prime minister Narendra Modi to work with other democracies to counter Mr Putin's aggression in Ukraine amid reluctance to publicly condemn the actions of Russia – a long-standing ally dating back to the Cold War.
Watch: Why Ukraine is exceeding expectations against Russia's air force.
India, which is heavily reliant on Moscow for arms imports, has abstained in a series of votes in the United Nations on the issue.
In the UK, the Prime Minister defended how quickly Ukrainians fleeing the conflict were being offered visas, as he was warned of the danger of refugee schemes turning into "Tinder for sex traffickers".
Mr Johnson said it was important that "checks both ways" were being carried out before Ukrainian refugees could come to the UK, both to ensure those in need were who they said they were, and also that those offering help were fit to do so.
Appearing in front of the Commons Liaison Committee, Mr Johnson said there had already been cases of "people coming from that war zone who may not be entirely who they say they are".
His comments came after it was revealed just 2,700 visas have been granted to people wanting to come to the UK under the Homes For Ukraine scheme despite applications reaching 28,300.