The foreign secretary rejected claims that the power and wealth of Russians in so-called “Londongrad” will prevent the UK – and the West as a whole – punishing Vladimir Putin’s aggression.
Ms Truss said legislation for new sanctions is imminent, alongside the expected sending of 1,000 further British troops to Estonia and warships to the Black Sea.
She rejected a claim that the cost to the UK would be “dramatic”, saying: “The most important thing is defending freedom and democracy and that is more important than immediate financial issues.
“We cannot favour short term economic interests over the long term survival of freedom and democracy in Europe – that’s the tough decision that all of us have got to make.”
The threat comes after ministers appeared to shelve long-promised ‘McMafia’ legislation, to target the unexplained wealth of kleptocrats – after many years of inaction.
US experts close to the White House have warned the wealth of kleptocrats invested in London – and their “close ties” to the Tory party – will thwart the UK’s pledges to act tough against Russia.
On the Trevor Phillips on Sunday programme, Ms Truss faced the accusation that “the cost of it to this country is dramatic”.
“For every Russian oligarch whose accounts are frozen, that means that somebody isn’t going to get investment from that Russian money in this country – for example, to support the levelling up agenda?” she was asked.
But Ms Truss said: “Currently, the economic sanctions are fairly narrowly drawn, so we could only target companies with a direct involvement in destabilising Ukraine.
“What we are looking to do is widen that, so any company of interest to the Kremlin and the regime in Russia would be able to be targeted, so there will be nowhere to hide for Putin’s oligarchs, for Russian companies involved in propping up the Russian state.”
On the threat of an invasion, the foreign secretary added: “We absolutely need to stop this happening. That is our number one priority.”
The UK is hardening its military response to the crisis, which threatens Europe with its most serious conflict since the Second World War.
Boris Johnson has offered to deploy jets to Romania and Bulgaria, warships to the Black Sea and the further 1,000 troops to Estonia, ahead of a Nato meeting on Monday.
The prime minister is expected to speak to Mr Putin tomorrow and travel eastern Europe early this week, to warn that thousands of lives will be lost if Russia invades Ukraine.
His plans could yet be derailed by the expected publication of Sue Gray’s heavily-censored report into the Partygate scandal – and he faces accusations that the trip is an attempt to distract from that controversy.