More than 800 asylum seekers arrived in Britain via small boats on Tuesday, the highest single-day figure since late 2022, adding to pressure on Prime Minister Rishi Sunak ahead of a July 4 national election.

Provisional data from Britain's interior ministry showed 882 migrants arrived on Tuesday, taking the yearly total so far to above 12,300. The daily figure was last higher in November 2022, when 947 migrants arrived in a single day.

Trailing far behind the opposition Labour party in opinion polls, and with immigration a major concern for some voters, "stopping the boats" and curbing illegal migration has been one of Sunak's flagship pledges.

The centrepiece of Sunak's immigration policy is a plan to deport asylum seekers from Britain to Rwanda and create a deterrent for migrants using small boats to cross from France.

But, because he calling the election earlier than many expected, that plan has yet to come into effect.

The opposition Labour Party, which is about 20 points ahead in opinion polls, has said it would scrap the Rwanda policy if it comes to power.

Instead, its proposed solution is to create a Border Security Command that would bring together staff from the police, the domestic intelligence agency and prosecutors to work with international agencies to stop people smuggling.