BRIGHTON, England (Reuters) – Britain’s Labour Party is ready to take charge of talks to leave the European Union and be “the grown ups in the room”, the party’s Brexit spokesman will say on Monday, attacking what he calls the “incompetence” of the ruling Conservatives.

Keir Starmer will use a speech at the main opposition party’s annual conference to press home a shift in policy on Brexit which sees Britain keeping full access to the EU’s single market during a transition period.

After months of sticking to a position little different from the Conservative Party’s pursuit of a clean break with the EU, Labour changed tack last month by suggesting the four-year transition period to smooth Britain’s departure in March 2019.

But while challenging Prime Minister Theresa May’s vision for Brexit, the shift has also put a spotlight on the divisions in the Labour Party. Some lawmakers are saying leader Jeremy Corbyn should go further and say, if in power, Labour would stay in the single market for the long term.

“Labour are now the grown-ups in the room,” Starmer will tell hundreds of Labour supporters in the southern English town of Brighton on Monday, according to excerpts of his speech.

“We stand ready to take charge of the negotiations. Not acting for narrow political gain. But in the national interest.”

Labour is riding high since winning more seats than it was expected to in a June election, when May’s attempt to win a stronger hand in the Brexit negotiations failed and lost her Conservatives their majority.

The party has capitalised on divisions in May’s cabinet of top ministers by offering what some call a “softer” vision for Brexit, saying that Britain has run out of time, largely because of that election, to negotiate a bespoke deal for transition.

“The way the Tories (Conservatives) are handling Brexit tells you a lot about their competence – or should I say incompetence,” Starmer will say, describing Labour’s approach as one that will “puts jobs and the economy first”.

DIVIDED

Labour’s move has attracted ‘remain’ voters from last year’s referendum, but the party is keen not to lose its supporters, mostly in northern England, who backed Brexit and have been reticent on how they see the future relationship with the bloc.

At its conference, packed with younger voters who have flocked to Corbyn as someone who can bring change, Labour members voted to debate issues other than Brexit, meaning a public discussion of EU policy was not on the official agenda.

Some more centrist members, part of a “Labour First” grouping, called it an “unprincipled and anti-democratic stitch-up designed purely to prevent the real differences of opinion” from being exposed.

“It’s just bizarre – conference won’t be able to vote on the biggest political issue facing the UK because it might harm the narrow factional interests of Momentum,” Labour First said in a statement, referring to the movement that backed Corbyn for leader.

But despite the criticism, Labour is unlikely to move much further on its Brexit position, with Corbyn saying only that he would listen to those who are calling for Britain to stay in the single market and customs union for the long term.

An instinctive eurosceptic, Corbyn told the BBC on Sunday: “I would also say that we need to look very carefully at the terms of any trade relationship because at the moment we’re part of the single market, obviously.”

“That has within it restrictions in state aid and state spending.”