The UK must exert “maximum pressure” on Russia to force the withdrawal of troops from Ukraine, the Scottish External Affairs Secretary has said, calling for the expulsion of the Russian ambassador and other diplomats.

Angus Robertson also insisted that Westminster must “change its policy and allow refugees from Ukraine to enter the UK” in the same way other European nations have done.

Scottish First Minister Nicola Sturgeon has already demanded the Home Office drop visa requirements for those arriving from Ukraine, as she pledged the Scottish Government “stands ready to assist and to play its full role in resettlement efforts”.

Mr Robertson said: “We have to have an open heart, we have to support the people of Ukraine. It’s their hour of need and we have to be there for them.

The idea that we should have Russian diplomats in the UK supporting the Kremlin’s lies about the war in Ukraine is intolerable

Scottish External Affairs Secretary Angus Robertson

He also told BBC Scotland’s The Sunday Show that Russian diplomats in the UK, including Ambassador Andrei Kelin, should be expelled.

“The idea that we should have Russian diplomats in the UK supporting the Kremlin’s lies about the war in Ukraine is intolerable,” he said.

“These are not normal circumstances, this is not the time for normal diplomatic relations.

“What (President Vladimir) Putin understands is power and what Putin understands is people who act and react to what he does.

“So not only should the Russian ambassador be sent back to Russia to explain that the UK is not ready to put up with what is happening, but we have Russian diplomats based in Scotland and we have to ask ourselves ‘Why are these are people here in support of Putin’s war in Ukraine?’. It’s intolerable.

“This is not status quo territory, this is unprecedented. This is the biggest war we have seen in Europe since World War II.

“It’s a full-scale war and we have to decide if we’re going to do everything we can.”

Britain, the United States, Canada and the European Union have already announced that some Russian banks will be excluded from the Swift global payment system.

They also said they would impose “restrictive measures” to prevent the Russian Central Bank from deploying its international reserves in a way that would undermine the impact of the sanctions.

Scottish External Affairs Secretary Angus Robertson called for “maximum pressure” to force Russia to withdraw its troops from Ukraine. (Andy Buchanan/PA)

This action could lead to “very, very rapid economic deterioration” in Russia, Robertson said.

“That’s how President Putin needs to feel, and we need to work with everyone to maximize the pressure on him so he realizes he can’t go on unchecked.”

He continued: “Unfortunately, we have passed the stage of deterrence with President Putin.

“What we need to do is make sure that we exert maximum pressure on the Russian government so that there is a price to pay for continuing this aggressive military campaign in Ukraine.”

With war in Ukraine likely to force higher food and energy prices, Mr Roberson said Britons needed to understand “there will be a cost”.

But he added: “War is even more costly, so let’s do what we can to help President Putin understand that he cannot continue this military aggression.

“Our friends in Ukraine need to know that we will do everything in our power to help them, in terms of humanitarian aid, military support and support for those seeking refuge elsewhere in Europe.

“Sanctions need to be tightened this week, governments need to talk to each other, we can always do more.”

He also said discussions were ongoing between the Scottish government and UK authorities over whether the tanker NS Champion – which is owned and operated by Sovcomflot, a wholly Russian government-owned company – should be allowed to dock in the British waters.

The vessel is due to arrive at Flotta Oil Terminal in Orkney on Tuesday, with Alistair Carmichael, Liberal Democrat MP for the islands, having raised concerns about it with Prime Minister Boris Johnson.

British authorities “have a big decision to make whether we are going to allow Russian or charter vessels to dock in UK ports,” Mr Robertson said.

“I don’t think it’s time to just business as usual, and the Scottish government is in discussions with the UK authorities over this very particular case, but there will be others.

“It’s a very good example of an area where we’re going to have to act decisively, in my opinion, because we can’t carry on as business as usual on the other side of Europe.”