LONDON, June 7 (Reuters) - Britain's top-selling newspaper the Sun on Wednesday urged its readers to ditch the opposition Labour Party and the anti-EU UK Independence Party and vote for Prime Minister Theresa May's Conservatives in Thursday's snap general election.
While the Conservatives are widely expected to win the vote, their opinion poll lead has narrowed significantly since May called the election and some surveys predict she could fail to win a majority.
UKIP, which played a key role in Britain's vote to leave the European Union last year, got nearly 13 percent of the vote in the last election in 2015 but now languishes at about 4 percent in the polls.
"The Tories (Conservatives) alone are committed to seeing Brexit through in full," the Sun wrote in a full-page editorial in its Wednesday edition, adding that UKIP no longer served any purpose.
"The Tories need every former UKIPper's vote to win a decent majority to make Brexit happen without opposition parties or rebellious MPs (members of parliament) holding it back."
The Sun, along with the broadsheet The Times, is owned by media mogul Rupert Murdoch and has a circulation of more than 1.6 million and is estimated to have a readership of more than double that.
After Conservative leader John Major's unexpected 1992 election victory, the newspaper carried the headline "It's the Sun wot won it", though its readership has fallen sharply since then.
The Sun article featured a cartoon of Foreign Secretary Boris Johnson pointing at the reader alongside the words "Your country needs you kippers to vote Tory", in a play on a famous British wartime recruitment poster "Your country needs you".
The newspaper said it did not believe Brexit would happen under Labour, and warned that electing a government led by left-wing Labour leader Jeremy Corbyn would be "the gravest mistake this country has ever made".
"The Tories have not run a great campaign but they are pro-business, pro-jobs and pro-low taxes. Most polls predict they will win, do not assume it," it said. "Make certain you vote tomorrow. Even if you haven't done so before, vote Conservative."
Britain's second highest selling newspaper, the Daily Mail, dedicated its first 10 pages to attacking Corbyn.
Its front page described Corbyn and two of his senior colleagues as "apologists for terror" who had "devoted their lives to befriending the enemies of Britain while undermining the very institutions that keep us safe in our beds".
The Daily Express newspaper, which supported UKIP at the 2015 election, also urged its readers to vote Conservative with "Vote May or we face disaster" splashed across its front-page.
The left-leaning Guardian newspaper has backed Labour ahead of the election, while the Economist last week dropped its support for May in favour of the pro-EU Liberal Democrats. (Reporting by Kylie MacLellan; editing by Diane Craft)