British lawmakers are due to vote on April 19 on Prime Minister Theresa May's plan for to hold a general election in June.
May’s motion to hold the snap poll on June 8 is expected to secure the two-thirds majority it requires in the House of Commons to go ahead.
Ahead of the vote, which is expected shortly after 1300GMT, May said an early election would strengthen her at the "most crucial point" in Britain's talks with the European Union on its exit from the bloc.
The opposition Labour Party and the Liberal Democrats welcomed the early elections, while the Scottish National Party (SNP) signaled its MPs will abstain in the vote.
May made the surprise call for the early poll on April 18, saying Britain needs certainty and stability in the wake of last year's Brexit referendum vote.
Britain's most recent general election was held in 2015 and the next one was to have been held in 2020.