LONDON — Britain’s revitalized Labour opposition kicked off its annual conference on Sunday with leader Jeremy Corbyn set to lay out his party’s agenda, free from the leadership challenges of previous years.

The left-of-centre party confounded expectations in June’s snap election by gaining an extra three million votes, a ringing endorsement for the anti-austerity programme of its veteran leftist leader.

His party is now polling higher than Prime Minister Theresa May’s governing Conservatives, unthinkable only a year ago when Corbyn had just won a leadership battle sparked by MPs angry at his lukewarm campaigning to stay in the European Union.

“The election has changed politics in this country,” Corbyn told The Guardian newspaper in a recent interview, adding that “the strength of the party” would be the focus of the conference in Brighton on England’s south coast.

“We are now the mainstream,” he insisted.

Labour has yet to set out a clear position on Brexit, particularly on what terms Britain will retain access to the EU’s single market.

Corbyn earlier this month called for “full access,” later adding “whether that’s formal membership — which is only possible, I believe, if you are actually a member of the EU — or whether it’s an agreed trading relationship, is open for discussion.”

The country will be looking for a clear indication of his plan, with 30 senior Labour figures writing an open letter calling for the party to do everything necessary to stay in the single market and the customs union.

However, Corbyn must also take into account the wishes of the millions of Leave voters in the party’s heartlands.

The leader told BBC’s Andrew Marr show on Sunday that he wanted tariff-free access to the EU market, but that there were “issues of state aid rules” that needed to be resolved in order that he could provide support for floundering industries, if he were prime minister.

Partly because of the dilemma, Corbyn ran an election campaign on domestic issues, a vote-winning tactic that he looks set to continue.

During a large open-air rally on the eve of the conference, the 68-year-old attacked the Conservatives as the “party of the rich, for the rich.”

“Our party plus our movement for social change” could create “a society that generally cares for all rather than the arid, nasty individualism that we inherited,” he said.

Even harsh critics such as The Economist magazine have acknowledged Corbyn’s success, splashing the headline “Britain’s most likely next prime minister” in its latest leading article.

“Not even Jeremy Corbyn could quite picture himself as leader of the Labour Party when he ran for the job in 2015,” it said.

“Now, with the Conservatives’ majority freshly wiped out and the prime minister struggling to unite her party around a single vision of Brexit, the unthinkable image of a left-wing firebrand in 10 Downing Street is increasingly plausible.”

Corbyn, who will speak on Wednesday — the conference’s final day — recently strengthened his hold over the party and his MPs, 80 percent of whom supported a motion of no confidence in their leader last year.

Conference motions are expected to reduce the power of Labour MPs and members of the European Parliament, as “Corbynites” reinforce their control over the party’s chief administrative body, the National Executive Committee, with trade union members and party members set for a larger say. — AFP