Elements of Russia's "playbook" are starting to appear in Ukraine as rumours continue to fly on when and how a Russian invasion into the country could happen.
The Prime Minister's official spokesman said ministers still believe Russia intends to mount an invasion of Ukraine, but added there is still a "window for diplomacy".
"Intelligence we are seeing suggests Russia intends to launch an invasion and President Putin's plan has in effect already begun," the spokesman said.
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"We are seeing elements of the Russian playbook we would expect to see in those situations starting to play out in real time.
"Crucially we still think there is a window for diplomacy."
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"I think that is what we have seen in discussions over the weekend and we want to explore those."
The spokesman said Defence Secretary Ben Wallace will make a statement to MPs later on Monday.
It comes after Boris Johnson warned a Russian invasion of Ukraine could result in the largest conflict in Europe since the Second World War.
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Mr Johnson said he wants people to "understand the sheer cost in human life" an incursion into Ukraine would cause, with casualties on both sides.
He also admitted hard-hitting financial sanctions may not be enough to prevent Russian President Vladimir Putin from signing off on an invasion.
Today, the Russian ambassador in the UK said Russia would "find ways to respond" to British sanctions.
He added that British efforts to build a united front in drawing up sanctions in the event of an invasion of Ukraine was a "huge overreaction to the unusual circumstances".
Russia has always denied it is planning to invade Ukraine.