Ms Patel's announcement came as the United Nations refugee agency said more than half a million people had fled Ukraine since the invasion on Thursday.

Most - estimated to be about 300,000 - have gone to Poland while others have fled to Romania and Hungary. And millions have left their homes.

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• Russia's football clubs and international sides suspended by FIFA and UEFA
• President Volodymyr Zelenskyy signs application to join European Union
• Britons 'willing to die' to defeat Putin's army as volunteers prepare to travel to fight

Ukrainian family members exempt from salary or language tests

Making the announcement in the Commons, Ms Patel said family members of those who are British nationals or have been given settled status - who do not meet the usual eligibility criteria but pass security checks - will be able to come to the UK for 12 months.

They will have to pass biometric and security checks but there will not be any salary or language tests, as are usually required.

Ms Patel said applications are being processed "in just hours" and said she is committed to ensuring the UK "is as generous as possible to the people of Ukraine, just as we have been to the people of Afghanistan and Hong Kong" in recent months.

She added that further announcements on Ukrainian refugees will be made "in due course".

No visa waiver for Ukrainian refugees

However, the home secretary said she would not be introducing a visa waiver because of fears that Russian troops and extremists could try and come to the UK.

Updating MPs on the government's latest efforts, Ms Patel said the UK's new "bespoke humanitarian route" for the people of Ukraine would "keep pace with the developing situation on the ground".

The home secretary told MPs this has "already supported hundreds of British nationals and their families resident in Ukraine to leave".

"The UK visas and immigration staff continue to work around the clock to assist them," she said.

Ms Patel added: "We are in direct contact with individuals and we've also lowered various requirements and salary thresholds so that people can be supported.

"Where family members of British nationals do not meet the usual eligibility criteria, but pass security checks, UK visas and immigration will give them the permission to enter the UK outside the rules for 12 months and is prioritising all applications.

"Giving British nationals and any person settled in the UK the ability to bring over their immediate Ukrainian family members."

Need to keep Britons safe

Outlining why she was rejecting calls for a visa waiver, the home secretary said she was following the "strongest security advice" in doing so.

"Security and biometric checks are a fundamental part of our visa approval process worldwide and will continue, as they did for the evacuation of people from Afghanistan," she said.

"That is vital to keep British citizens safe and to ensure that we are helping those in genuine need, particularly as Russian troops are now infiltrating Ukraine and merging into Ukrainian forces.

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"Intelligence reports also state the presence of extremist groups and organisations who threaten the region but also our domestic homeland.

"We know all too well what Putin's Russia is willing to do, even on our soil, as we saw through the Salisbury attack."

The home secretary also revealed the UK has asked for Russia to be suspended from its membership of Interpol, telling the Commons: "We'll be leading all international efforts to that effect."

On Monday evening, the government was defeated three times as peers in the House of Lords voted on the controversial Nationality and Borders Bill.

Peers backed an amendment to allow descendants of a person born before 1983 on the Chagos Islands to register as a British Overseas Territories citizen as a British citizen.

They also supported a move to scrap people being stripped of their British citizenship without warning and voted in favour of an amendment that means the bill will have to comply with the UK's international commitments to refugees.