A senior Conservative MP has said the government could protect Brits by expelling Russian citizens from the UK in response to Vladimir Putin's invasion of Ukraine.
The Russian president announced in the early hours of Thursday morning that he would invade Ukraine, and warned the West it would face the "greatest consequences in history" if it interfered.
US, Nato and EU leaders have responded with a new wave of punitive measures.
Late on Thursday, Boris Johnson announced a fresh series of 10 main sanctions, targeting around 100 Russian individuals (including Putin's former son-in-law), entities, subsidiaries and banning any business with them in the UK.
Other measures include the government freezing all the assets of the major Russian banks - including the country’s second largest VTB - totalling £154bn.
In parliament on Thursday afternoon, the Conservative MP and foreign affairs select committee chair Tom Tugendhat called for tougher consequences on Russian individuals to protect Britain.
“A hostile state has launched an act of war, we can act now," he said.
"We can freeze Russian assets in this country, all of them.
"We can expel Russian citizens, all of them... We can make a choice to defend our interests, to defend the British people, and to defend our international partners.
"Or we can do, sadly, what we’ve done too often in the past: watch, until it’s too late, and the British people have to pay a much higher price.”
Speaking in the House of Commons as he announced the sanctions, Johnson said it was "vital" Putin is seen to fail.
"Above all, the House will realise the hard and heavy truth that we now live in a continent where an expansionist power, deploying one of the world’s most formidable machines, is trying to redraw the map of Europe in blood and conquer an independent state by force of arms," he said.
“And it’s vital for the safety of every nation that Putin’s squalid venture should ultimately fail and be seen to fail. "
The UK - like the rest of Nato - has ruled out sending troops to fight against Russian forces as Ukraine is not a Nato country.
Senior Conservative MP, David Davis, said on Thursday morning that the West should send military support to Ukraine, saying Putin had "effectively" waged war on The West, too.
"There are no zero-risk options. If we do not act militarily, then Nato will be significantly weakened and we must fear for the safety of every state that borders Russia," said Davis.
He added: "Ultimately it is a trade-off between two outcomes - whether we defend the democratic rights of more than 40 million Ukrainians or fail to act now and be forced to act later but at a possible greater cost."
Watch: Ukraine invasion: Boris Johnson unleashes UK's 'largest set of sanctions ever' on Russia - Putin's former son-in-law targeted