The UK Parliament was formally dissolved on Thursday ahead of the July 4 general election.
Five weeks of campaigning officially began as 650 seats of members of parliament (MPs) became vacant in line with the electoral schedule.
UK Prime Minister Rishi Sunak made surprise decision last week calling for a snap general election.
Some 129 MPs have so far announced that they will not be standing for re-election. Among them are 77 Conservatives, an unprecedented exodus for a governing party.