Britain's Prime Minister Theresa May delivers a campaign speech in central London, Britain, June 5, 2017. REUTERS/Hannah McKay

LONDON (Reuters) - Prime Minister Theresa May is on track to win 305 seats in Britain’s parliament in an election on Thursday, 21 seats short of a 326-seat majority, according to a projection by polling company YouGov on Monday.

May’s Conservatives had 330 seats when the snap election was called in April.

On Saturday, YouGov said its model suggested the Conservatives were on course to win 308 seats.

The opposition Labour Party is likely to win 268 seats, YouGov’s model showed on Monday, up from 261 on Saturday.

Another model, produced by Lord Ashcroft Polls, last week predicted the Conservatives were on course for a majority.