A Ukrainian-born Tory donor has begged Boris Johnson to impose a no-fly zone over Ukraine – as he labelled Vladimir Putin “insane”.

Alexander Temerko has asked the prime minister to reconsider his objections to a no-fly zone, arguing it could save the lives of millions of people.

The veteran Tory donor, who gained British citizenship in 2011, argues the threat of nuclear retaliation by Russia is low because the generals and colonels who carry out the instruction would not obey.

However, he said that the US and UK should at least consider a no-fly zone over western Ukraine if they do not think it is feasible to protect the whole country.

Follow live updates on the Ukraine invasion

Please use Chrome browser for a more accessible video player

He told Sky News: “Putin understands that he can lose his army in western Ukraine. And he will assault and bomb Ukraine with missiles.

“That will be a huge humanitarian catastrophe if it happens next week.

Ukraine invasion: Russia completely blocks Facebook and restricts access to Twitter

Gas prices scrape record highs in the UK as market trembles

Ukraine invasion: Three Russian commanders killed so far – and Kyiv convoy stuck in ‘enormously large traffic jam’, Western officials say

“And today, President Zelenskyy and the Ukrainian diaspora across the whole world call on governments to please use their authority to make a decision to close the airspace around Ukraine.

“If you cannot create a non-flight area across Ukraine, do it in the western part of Ukraine. That is a drastic and vital decision to save the life of millions of people.”

Read more: What’s a no-fly zone and why won’t the West enforce one in Ukraine?

Please use Chrome browser for a more accessible video player

Mr Temerko, who worked in Russia’s defence ministry in the 1990s, suggested that the military command would not automatically obey.

“Putin can give the command,” he said. “It’s possible because he’s insane and an unpredictable person, very poorly informed.

“But I don’t believe that at the middle level – generals and colonels – would fulfil or perform his order. Most of them have a family, they love their family, they love their life, and they understand consequences.”

However, he stopped short of calling Mr Putin evil: “I think he’s insane, not evil. He is paranoid and far from reality.”

The Conservative Party has received £1.6m from Mr Temerko, either directly or from companies he is involved in.

He has given money directly to more than 20 Tory MPs and speaks to Mr Johnson directly, with pictures of them together in his office.

More: British police appeal to victims of war crimes in Ukraine to contact them

Please use Chrome browser for a more accessible video player

The donor is now seeking to bolster the humanitarian and security effort to defend Ukraine, arguing that it is necessary to protect democracy.

Mr Temerko was born in southern Ukraine when it was under the control of the USSR. Today, the area he grew up in is largely under Russian military control.

He said: “Today, my home place is under the pressure of the Russian army. It’s actually in ruins. My school is absolutely destroyed by Russian shelling.

“I spent a lot of time in Mariupol. Today that is a symbol of heroism of the Ukrainian army and the courage of the Ukrainian army.

“They are fighting against Russian forces and today the whole city is a proper battlefield.

“A lot of houses destroyed, killed people, civilians are underground in basements, but they are fighting for every house and every street. That is a very, very heroic act.”

Please use Chrome browser for a more accessible video player

Mr Temerko told Sky News he wanted the UK and EU to impose sanctions on Russian gas, even though it will mean a big rise in energy bills, petrol, and the cost of living.

“[Blocking Russian energy supplies] is absolutely the right way. The Russian energy sector is a pillar,” he said.

“It’s one of the pillars of the Russian economy. If you destroy the Russian economy, you destroy the Russian military machine as well.”

Pressed how much the price of fuel would go up, he replied: “Maybe at least 30% from current costs. It’s a price for democracy.”

Related posts:

Hancock says vaccine rollout a ‘huge team effort’ after Cummings calls his department ‘smoking ruin’ PM: No change to roadmap out of lockdown despite UK facing cut in vaccine supply No more isolation for fully vaccinated arrivals from France, as India moved off red list Priti Patel visits Greece for discussions on tackling illegal migration No ‘free-for-all’: Wales set to move to alert level zero – but FM warns it ‘does not mean end of restrictions’ Geronimo the alpaca set to die after No 10 refuses stay of execution World on the brink of ‘catastrophe’ as extreme weather events pile up, UK’s climate chief warns ‘Sausage war’ truce holds as UK indefinitely extends grace period for post-Brexit checks PM refuses to rule out more tax rises ahead of next election as he defends National Insurance hike 12 to 15-year-olds to get ‘final say’ over COVID jab if disagreement with parent occurs National Insurance hike will see care workers receive tax rise but no pay increase – Starmer Extra 100,000 Ukrainians will be able to seek sanctuary in UK, home secretary says