Explained | What is the UK's Rwanda migrant deportation plan?

London: The British Parliament will hold two days of debate over Prime Minister Rishi Sunak's bill designed to allow Britain to send asylum seekers who arrive illegally in Britain to Rwanda amid deep divisions in his Conservative Party on the issue.

Last November, the UK Supreme Court declared the policy unlawful and Sunak hopes the new legislation, when passed, will override legal concerns and fulfill his pledge to stop people arriving across the Channel in small boats.

Here are details about the plan and the migration issue:

Why is immigration such an issue in Britain?

Taking back control of borders and ending the free movement of people was a major factor that led to the 2016 vote for Britain to leave the European Union. Polls show it remains one of the most important issues for voters.

Successive Conservative governments had previously promised to limit net migration to under 100,000 annually. But in 2022 it hit a record of 745,000, partly due to new visa routes for arrivals from Ukraine and Hong Kong.

In response, Sunak's government has announced a series of measures that could slash that number by 300,000.

Meanwhile, more than 29,000 people were detected coming on small boats to England's southern beaches without permission last year, after a record 45,775 migrants arrived in 2022.

So far this year, 263 people have made the dangerous journey of about 20 miles (32 km) across the Channel. On Sunday French authorities said five migrants died attempting to make the crossing.

What is Britain's Rwanda plan?

The Rwanda scheme, agreed in April 2022 by then Prime Minister Boris Johnson, is designed to deter migrants from coming to Britain illegally and break the business model of people smugglers.

Under the plan, anyone who arrived in Britain illegally after Jan. 1, 2022, faced being sent to Rwanda, some 4,000 miles (6,400 km) away.

However, the first deportation flight in June 2022 was blocked by European judges.

The UK Supreme Court then unanimously upheld a ruling that the scheme was unlawful because migrants were at risk of being sent back to their homelands or to other countries where they would be at risk of mistreatment.

Despite no deportations taking place, Britain has already paid Rwanda 240 million pounds. While Britain hopes to send thousands of migrants, at the moment Rwanda only has the capacity to take a few hundred.

Why is the Rwanda policy so important to Sunak?

After becoming prime minister in October last year, Sunak made "stop the boats" one of his top five priorities.

Britain is currently spending more than 3 billion pounds a year on processing asylum applications, with the cost of housing migrants awaiting a decision in hotels and other accommodation running at about 8 million pounds a day.

At the start of the year Sunak said he had met a pledge to clear a so-called 'legacy backlog' of 92,000 asylum claims which were made before a June 2022 change in immigration law, although figures show about 100,000 applications still remain to be decided.

What is Sunak's Rwanda bill?

To address the issues raised by the Supreme Court, Sunak agreed a new treaty with Rwanda that seeks to prevent anyone from being sent anywhere else other than back to Britain.

A new "emergency' bill" which the government stated might not be compatible with the European Convention on Human Rights, is also currently going through parliament to affirm that Rwanda is a safe country.

It disapplies some sections of Britain's Human Rights Act and says ministers alone would decide on whether to comply with any injunction from the European Court of Human Rights. If passed, Sunak says flights to Rwanda will begin early this year.

Will parliament pass Sunak's Rwanda bill?

Some legal experts say as the bill stands, Britain would still be bound by findings of the European Court of Human Rights which could again issue injunctions to block deportation flights.

That has angered Sunak's right-wing Conservative critics who have warned they could vote down the bill. His government has a working majority of 56 in the House of Commons, meaning in theory that if 29 of his lawmakers rebel, he could lose a vote.

In the first vote in parliament last month, the bill passed by 313 votes to 269 when about 30 right-wing Conservatives abstained. They have threatened to vote against it at a later stage unless it is toughened up.

More than 50 lawmakers have backed amendments to change the bill to ensure deportations could not be blocked by either British or European judges. These will be considered when the bill is discussed by parliament on Tuesday and Wednesday.

The government says while the law must permit individual challenges, the opportunities to do so were extremely limited. Sunak has said the bill can go no further and is already pushing at the limits of complying with international law.

Meanwhile, other Conservative lawmakers have indicated they would not support a bill which put Britain in breach of international law.

Even if Sunak gets the bill through the House of Commons, the legislation could still be held up by the unelected upper chamber, the House of Lords, preventing it from becoming law before an election expected in the next year.

The Labour Party, which is ahead in opinion polls, has pledged to scrap the policy if it wins the election.

How does Britain compare with other countries?

Many European nations such as Germany have tightened their border controls to address immigration concerns, while the European Union has agreed a new deal on how to share out the cost and work of hosting migrants more evenly.

Denmark has also signed a similar agreement with Rwanda, but has yet to send any migrants there, and Italy has announced plans to build reception centres in Albania.

Israel scrapped a similar deal with Rwanda in 2018 after five years, with the Israeli Supreme Court declaring it unlawful because Rwanda had not complied with assurances it had given.