MPs have given a standing ovation to the UK's Ukrainian ambassador in a rare show of solidarity.

Prior to Prime Minister's Questions, Commons speaker Sir Lindsay Hoyle welcomed Vadym Prystaiko, the country's top diplomat, who was watching the session from a gallery above the main Commons chamber. 

MPs from all parties stood to applaud him, fter which Sir Lindsay joked: "We generally do not allow applause in this Chamber, but on this occasion the House quite rightly wants to demonstrate our respect and support for your country and its people in the most difficult circumstances."

The Herald: Vadym Prystaiko, gives a 'V' gesture as he arrives in Downing Street. Image: PAVadym Prystaiko, gives a 'V' gesture as he arrives in Downing Street. Image: PA

Many MPs could be seen wearing the colours of the Ukrainian flag - blue and yellow - including former Prime Minsiter Theresa May, and the SNP's Alison Thewliss, who were both dressed in blue and yellow clothing.

Many of the male MPs worse blue shirts and yellow ties in a show of solidarity with the war-torn country.

Ian Blackford, the SNP's Westminster leader, urged Boris Johnson to agree with the prosecution of 'crimes of aggression by the state' in an international criminal court - a charge the UK have previously refused to support.

Mr Blackford argued that Vladimir Putin was a "war criminal" and should be charged with this crime.

However Mr Johnson said he was convinced Putin had already committed war crimes based on the evidence of attacks against Ukraine, and the types of weapons being used.

He said: "What we have seen already from Vladimir Putin’s regime in the use of the munitions that they have already been dropping on innocent civilians, in my view, already fully qualifies as a war crime and I know that the ICC prosecutor is already investigating, and I am sure the whole House will support that.”

Labour leader sir Keir Starmer aquestioned the Prime Minister about why Roman Abramovich and other prominent wealthy Russians had not yet been sanctioned by Westminster.

He said: "We must stand up to Putin and those who prop up his regime.

“Roman Abramovich is the owner of Chelsea Football Club and various other high-value assets in the United Kingdom. He’s a person of interest to the Home Office because of his links to the Russian state and his public association with corrupt activity and practices.

“Last week, the Prime Minister said that Abramovich is facing sanctions. He later corrected the record to say that he isn’t. Well, why on earth isn’t he?”

Mr Johnson said he could not comment on indiuvidual cases, but insisted the UK would  keep working to "tighten the noose around Putin’s regime”.

He added that a “full list of all those associated” with the Russian president’s regime will be published.

MPs also urged the Prime Minister to go further in offering safe passage for Ukrainians fleeing their homes to come to the UK.

However Mr Johnson insisted that the goevrnment has already loosened the restrictions, and security checks would not be given up completely as they were crucial to ensure safety of the UK.