Britain has sent a first asylum seeker to Rwanda, British media reported on Tuesday, a week after adopting a controversial law allowing irregular migrants to be deported to the east African country.

Prime Minister Rishi Sunak's government has made the fight against illegal migration a priority as it hopes to recover ground on the main opposition Labour party ahead of an expected general election later this year.

The announcement of this expulsion comes just two days before local elections in England and Wales in which the ruling Conservatives are expected to suffer major losses to Labour.

The controversial law, which has come under fire from the United Nations and rights groups, allows Britain to expel undocumented migrants to Rwanda, where they would be allowed to remain if their asylum applications are successful.

They would not be allowed to return to Britain.

Sunak's government plans to begin the expulsions by July.

But the man who left the UK on Monday had agreed to be sent to Kigali following his asylum rejection at the end of last year, several media said, as part of a separate and voluntary scheme.

The African national left on a commercial flight to Kigali, The Sun newspaper said.

In exchange for his agreement to leave Britain, he is due to receive up to £3,000 ($3,750), according to government sources quoted by the Times newspaper.

- 'Rebuild their lives' -

Contacted by AFP, the British Home Office did not confirm the reports.

"We are now able to send asylum seekers to Rwanda under our migration and economic development partnership," a government spokesperson said.

"This deal allows people with no immigration status in the UK to be relocated to a safe third country where they will be supported to rebuild their lives."

The Tories hope the Rwanda expulsions plan will help them claw back some ground in the polls.

They are widely expected to suffer a drubbing at the next general election.

The British government on Tuesday said it expects to deport 5,700 migrants to Rwanda this year in the scheme aimed at deterring migrant arrivals on small boats from northern Europe.

More than 57,000 people arrived on small boats after trying to cross the Channel between January 2022 and June last year, according to official statistics.

A record 45,000 migrants crossed the Channel in 2022 but already more than 7,200 people did so in the first four months of this year -- a historical high for the period.

Rwanda, home to 13 million people in Africa's Great Lakes region, lays claim to being one of the most stable countries on the continent and has drawn praise for its modern infrastructure.

But rights groups accuse veteran President Paul Kagame of ruling in a climate of fear, stifling dissent and free speech.