Boris Johnson has warned Russian president Vladimir Putin that invading Ukraine would lead to a “painful, violent and bloody business”.

       The prime minister said the intelligence around the situation was “gloomy” but war was not inevitable – urging Russia to pull back from a “disastrous step”.

       Mr Johnson said Ukraine would “fight” if invaded, comparing the potential combat to the decades-long Chechen–Russian conflict. “It’s very important that people in Russia understand that this could be a new Chechnya.”

       Speaking to reporters as the Foreign Office pulled some British embassy staff out of Ukraine capital Kyiv, he said: “We do think it prudent to make some changes now.”

       The prime minister added: “The intelligence is very clear that there are 60 Russian battle groups on the borders of Ukraine, the plan for a lightning war that could take out Kyiv is one that everybody can see.”

       Recommended Electricity blackouts could hit Europe, experts warn PM says ‘we have to pay’ for NHS as he defends national insurance hike Transparency of Gray report questioned amid claims staff kept back evidence

       Mr Johnson added: “We need to make it very clear to the Kremlin, to Russia, that that would be a disastrous step.”

       Some British embassy staff and their dependants are being pulled out of Kyiv in response to the mounting Russian threat to Ukraine.

       The Foreign Office confirmed the move after the US ordered the families of all American personnel at the US Embassy to leave the country in response the the risk of an invasion.

       Russian forces have massed at the border with Ukraine and intense diplomatic activity has failed to ease tensions.

       The prime minister said he would speak to fellow western leaders later on Monday, and claimed the UK was “leading” on the west’s package of economic sanctions against Russia should they invade.

       “We need to get over the message that invading Ukraine, from a Russian perspective, is going to painful, violent and bloody business,” Mr Johnson warned.

       He said: “I’ve been the Ukraine several times, I know the people of that country a bit. My judgement is that they will fight. And really, that is not the way the world should be going. I hope they understand that in the Kremlin.”

       Mr Johnson added: “But it’s the job of the UK to make sure our friends and partners around the world, particularly in Europe, also understand that, and we get ready a tough enough package of sanctions.”

       Recommended Cummings claims fearful No 10 staff are keeping evidence from party inquiry Why does Russia want to block Ukraine from joining Nato? Johnson: Russia planning ‘lightning war’ to take out Kyiv

       It follows foreign secretary Liz Truss’s accusation that Mr Putin of plotting to install a pro-Moscow leader as head of the Ukrainian government.

       The Foreign Office took the unusual step of naming former Ukrainian MP Yevhen Murayev as a potential Kremlin candidate to take over in Kyiv – a claim dismissed as provocative “nonsense” by Moscow.