BRITS still in Ukraine were today given a final warning to get out of the country now with a Russian invasion “very imminent”.
Bombs and missiles could rain down on cities including the capital Kiev within minutes of Vladimir Putin ordering the attack.
And armed forces minister James Heappey warned there will be no chance of an Aghanistan-style airlift out for stranded civilians.
UK and US intelligence says the Kremlin has now moved the last military units into place needed for a full scale invasion.
Spooks believe Moscow is likely to launch a false flag operation, such as a fake attack on Russian citizens, to justify a war.
Mr Heappey today warned “all the conditions are set for Russian to launch an attack” and it “could happen with no notice”.
He said: “I’m being very, very clear to people that they should leave Ukraine now whilst there are the commercial means for them to do so, and whilst the motorways are available for them to drive out over the border.
“This isn’t a warning about something that could happen in three months’ time. This isn’t a warning that would be followed by further warnings.
“This is a warning because minutes after Putin gives the order missiles and bombs could be landing on Ukrainian cities.”
Mr Heappey warned any British citizens left in the country after a war starts may not be able to get out.
There would be no chance for the UK, US, and other Western countries to mount an Afghanistan-style rescue operation.
That’s because advanced Russian weapons like heavy artillery and fighter jets would make the skies above Ukraine too dangerous.
He said: “Even if that was something that we wanted to do, the reality is that we just couldn’t.
“What you end up with a highly contested complex airspace that just makes it impossible to mount that sort of rescue effort.”
His stark warning comes with Boris Johnson this week launching a fresh diplomatic blitz to try and avert a war.
The PM will hold a series of calls with world leaders and travel to Europe later this week as he urges Vladimir Putin to “step back from the brink”.
Defence Secretary Ben Wallace – who yesterday cut short a family holiday because of the Ukraine crisis – will attend a meeting of Nato Defence Ministers in Brussels in the coming days.
Russia has amassed a terrifying force of 130,000 troops at the Ukraine border and is thought to be planning to invade any day now.
As tensions flare, the West is expected to announce a new package of economic and defensive support for Ukraine within days.
Issuing their starkest warning yet, a Downing Street spokesman said: “The crisis on Ukraine’s border has reached a critical juncture.
“All the information we have suggests Russia could be planning an invasion of Ukraine at any moment.
“This would have disastrous consequences for both Ukraine and Russia.
“There is still a window of opportunity for de-escalation and diplomacy, and the Prime Minister will continue to work tirelessly alongside our allies to get Russia to step back from the brink.”
As Europe teeters on the brink of war, the PM has vowed to do everything he can to stop a Russian invasion.
Britain is arming Ukranians and has threatened Moscow with crippling economic sanctions if one Russian toe cap crosses the border.
The UK military is massively beefing up its troop presence in neighbouring Nato countries like Estonia, and has sent two ships to the Eastern Med and Black Sea.
We now have an entire RAF squadron on standby ready to police the skies in Nato’s South East corner.
Mr Johnson, who is receiving daily intelligence briefings on the crisis, is keen to work with the Nordic and Baltic countries on Russia’s border.
He wants to show Putin that he faces a wall of opposition if he sends troops over the border.
All Brits have been urged to leave Ukraine, with just a small group of diplomats left to oversee the mission there.
In a blistering interview at the weekend, Mr Wallace said some of the last ditch diplomatic efforts to avoid war has the “whiff of Munich” and appeasement.
He said an invasion is now “highly likely” and poured scorn on those who naively think Mr Putin will have a sudden change of heart.
He said: “It may be that he [Putin] just switches off his tanks and we all go home, but there is a whiff of Munich in the air from some in the West.”
He added war in Ukraine will trigger a massive refugee crisis in Europe.
“I definitely have a genuine fear about what it means for European security,” he said.
“The potential of millions of displaced people — refugees — pouring from [one] European country to another, hasn’t been seen since the war and could potentially have a massive impact.
“I worry about why a president of Russia would do this when he doesn’t need to and what that says about him as a leader.”
WEST ‘ASLEEP AT WHEEL’
Tonight, sources close to Mr Wallace scrambled to clarify his Munich remarks amid a backlash – insisting he was not having a go at allies.
Instead they said it was a barb aimed at Putin, who Mr Wallace fears has already decided to invade “come what may” and regardless of diplomatic efforts.
Ukraine’s ambassador to the UK, Vadym Prystaiko, criticised Mr Wallace for the Munich comment.
He said: “It’s not the best time for us to offend our partners in the world, reminding them of this act which [did not bring] peace but the opposite, it bought war.
“There’s panic everywhere not just in people’s minds but in financial markets as well.”
Tory MP and defence select committee chairman Tobias Ellwood said the West has been “asleep” at the wheel and failed to realise the threat from Russia:
He said: “We need to wake up to our responsibilities, to defend the international rules-based order.
“I don’t doubt the scale of where things are ratcheting.
“This is our Cuban missile crisis, but right now it’s us that is blinking and not Putin.”