Britain will Tuesday introduce new legislation to crack down on "dirty money" and corrupt elites as it ramps up its campaign to hit Russian finance over Ukraine.

The move comes after the government took flak over its response to date to choke off the years-long flow of rich Russians' hot cash into the United Kingdom, where it has infiltrated financial and property markets.

Moscow's invasion of neighbouring Ukraine has brought a long-debated issue to a head, moving London to introduce a "Register of Overseas Entities" to crack down on money laundering by foreign criminals.

The new register will require anonymous foreign owners of UK property to reveal their real identities and ultimate "beneficial owner", meaning they can no longer hide behind shell companies as Britain sets "a new global standard for transparency".

Failure to comply could bring punishment of up to five years in prison.

"There is no place for dirty money in the UK," said Prime Minister Boris Johnson.

"We are going faster and harder to tear back the facade that those supporting (Russian President Vladimir) Putin's campaign of destruction have been hiding behind for so long.  

"Those backing Putin have been put on notice: there will be nowhere to hide your ill-gotten gains," added Johnson as Home Secretary Priti Patel hailed what she termed "unprecedented action in the face of barbaric Russian aggression".   

Insisting that "time is up for Putin's cronies hiding dirty money in the UK", Patel said the legislation would strike a blow against financial crime.

Business Secretary Kwasi Kwarteng said the register "will shine a light on who owns what in the UK so we can flush out the oligarchs, criminals and kleptocrats who think they can use UK property to hide their illicitly obtained wealth".

'Londongrad'

The legislation will streamline procedures for issuing Unexplained Wealth Orders to those suspected of having obtained cash through corrupt means.

The Orders were introduced in 2018 in an attempt to tackle corruption and money laundering on British soil.

The revamped legislation will apply retrospectively to the owners of properties obtained by foreign nationals over the past 20 years in England or Wales and since December 2014 in Scotland.

Russian billionaires have in recent decades acquired extensive assets -- notably in real estate -- in some of London's swankiest districts, leading to the city earning the nickname "Londongrad" and to NGOs and British officials sounding the alarm.

Four years ago, even before the emergence of the Ukraine crisis, Britain's National Crime Agency estimated Russians were laundering hundreds of billions of pounds through the country every year.

The Ukraine crisis has already seen one high-profile symbol of Russia's oligarchy, Russian-Israeli billionaire Roman Abramovich, moved to hand over control of Premier League football club Chelsea, although he will remain as owner.

The British government has already frozen the assets of Putin and his Foreign Minister Sergei Lavrov as well as sanctioning a raft of Russian businessmen and banks.