LONDON - Human rights groups said they had submitted papers at the High Court in London on Wednesday to get an injunction to halt next week's planned deportation of asylum seekers from Britain to Rwanda, a scheme that has drawn widespread criticism.

Britain's government announced in April it had struck a deal to send potentially tens of thousands of asylum seekers to the East African nation in a bid to undermine people-smuggling networks, and stem the flow of migrants risking their lives by crossing the Channel in small boats from Europe.

The first flight taking the migrants to Rwanda is expected next week, the Conservative government has said.

Charities Care4Calais and Detention Action along with the Public and Commercial Services Union (PCS), which represents civil servants in Britain's interior ministry, said lawyers had now submitted papers seeking a judicial review of the scheme, and an injunction to block the June 14 flight.

"It’s vital that new government policies respect and uphold the laws that we all, as a society, have agreed to follow," said James Wilson, Deputy Director of Detention Action. "That’s why we're seeking an injunction to keep this plane to Rwanda from leaving the runway."

There was no immediate comment from the Home Office (interior ministry).

Concerns over immigration were a big factor in the 2016 vote for Britain to leave the European Union, and Prime Minister Boris Johnson has been under pressure to deliver on his promise to "take back control" of Britain’s borders.

Last year, more than 28,000 migrants and refugees made the crossing from mainland Europe to Britain. In November, 27 people drowned when their small rubber dinghy deflated, and many others have needed to be rescued from the narrow seaway, one of the world's busiest shipping lanes.

Under the government scheme, anyone who has arrived in Britain illegally since Jan. 1 could be relocated to Rwanda, whose own human rights record has been criticised by humanitarian groups.

The plan has raised an outcry not just among human rights groups but also opposition left-wing and liberal lawmakers as well as some in Johnson's Conservative Party.

(Additional reporting by Lucy Marks, Editing by Mark Heinrich)