Mr Deripaska, an industrialist who has had close ties to Britain’s political establishment, was targeted for government sanctions last week.

The four men, who initially told reporters there were five of them, have been sitting on the edge of the balcony, surrounded by police inside and outside the building, for more than an hour.

The street was also cordoned off with at least 10 police vehicles and at least 32 officers visible at the scene.

The Metropolitan Police told the PA news agency the number of officers was part of a “flexible and proportionate response”.

Officers wearing harnesses initially attempted to deploy a ladder to gain access to the balcony, but after the squatters sat in the way to obstruct them, a JCB crane was moved to lift them instead.

Police in riot gear also used a drill to force open the front door and enter the house.

Scotland Yard said in a statement: ‘Officers have completed a search of the property in Belgrave Square and are satisfied there are no protesters inside.

“We continue to engage with those on the balcony as we balance the need for enforcement with the safety of everyone involved.”

Speaking to the PA news agency by phone, one of the protesters, who declined to be named but said he was from Lithuania, said: ‘Our whole group has made peace with the arrest because that was always one of the options.

“I’m ready to take the consequences of something I believe in.”

He also said they did “everything right” and left “no criminal damage” in the property.

The man said that although he does not know why the police might have arrested or charged him, he “would like to go to court and prove what I mean”.

“This house could house 200 people. We have done a job that the government should be doing. We have freed up the property for the refugees,” he added.

Describing the house, he said: ‘It’s huge. I got lost I don’t know how many times.

“There are so many useless rooms, there is a cinema, a lot of expensive paintings. No one deserves all this.

When asked how they got into the property, he joked, “Squatter magic with some climbing skills.”

The squatters call themselves London Mahknovists – after Nestor Makhno, who led an anarchist force that attempted to form a stateless society in Ukraine during the Russian Revolution of 1917-1923.

They hung a Ukrainian flag as well as two signs reading “this property has been liberated” and “Putin fuck you.”

They also danced, played music and a man sang lines from the song Dirty Dancing (I’ve Had) The Time Of My Life.

“We stay here until Putin stops the war,” one man told reporters.

He continued, “We opened the building to accommodate Ukrainian refugees and refugees from all nations.

They said the British government had “failed” to respond properly to the invasion. The group also criticized the police, comparing them to those arresting protesters in Russia.

A statement from the Metropolitan Police said earlier: ‘Police were called shortly after 1am on Monday March 14 to a residential property in Belgrave Square, SW1.

“Officers attended and found that a number of people had entered and hung banners from upstairs windows.

“Officers are staying put.”

Mr Deripaska has been described as “a prominent Russian businessman and pro-Kremlin oligarch”, who is “closely associated” with both the Russian government and President Vladimir Putin.

His fortune is estimated at £2.3billion and he has a multi-million pound property portfolio in the UK which, according to a 2007 High Court judgment, includes the house at 5 Belgrave Square. Records indicate that it has not changed hands since and is owned by an offshore company in the British Virgin Islands.