Liverpool (AFP) – Dismissed as a shadowy group of Marxist infiltrators or hailed as a grassroots movement energising left-wing politics, the campaign organisation Momentum, which backs Labour leader Jeremy Corbyn, is unsettling British politics.

Momentum grew out of Corbyn’s campaign to lead the main opposition Labour party last year, and now counting 18,000 members, has been vigorously supporting his efforts to fight off a leadership challenge by Owen Smith.

Leftist stalwart Corbyn, 67, is expected to be reconfirmed as leader on Saturday at the party conference in Liverpool.

However, the leadership contest has exposed a deep divide over the future direction of the historic party — with Momentum driving demands for change.

The group is not affiliated to Labour and is — at least officially — run separately, but it claims to be working towards creating a socialist Labour government based on Corbyn’s views of nationalisation and redistribution of wealth.

Organisers say it is funded by small donations, proving how it has struck a chord with ordinary people who felt left behind with mainstream politics.

Yet the enthusiasm of its activists have prompted accusations that Momentum “thugs” are intimidating Labour MPs who disagree with Corbyn, many of them centrists who belive their leader can never win power.

Smith, who stood against Corbyn after a rebellion by 80 percent of Labour MPs, has likened Momentum to a parasite, accusing it of trying to de-select 170 of the party’s MPs as part of a bid for control.

It is “trying to use our movement as a host body, seeking to occupy it, hollow it out, until it’s outlived its usefulness, when you throw it aside like a dead husk”, he said in a speech last week.

Deputy Labour leader Tom Watson also warned recently that sympathisers of Marxist Leon Trotsky, who were driven out of Labour decades ago, were now returning.

“They are caucusing and factionalising and putting pressure where they can, and that’s how Trotsky entryists operate,” he told The Guardian newspaper.

– Stagnation of parties –

Momentum is open about its desire to transform Labour into a “more open, member-led party with socialist policies” and to press for the election of candidates that reflect those views, as it says on its website.

But national organiser James Schneider dismisses claims of infiltration as “complete nonsense” and denied plans to de-select hostile Labour MPs.

“Momentum can’t possibly infiltrate the Labour party because it’s made up of Labour party members, affiliates and supporters of the Labour party,” he told AFP.

He added: “The whole purpose of what we’re trying to do is to win a Labour government, a government that will have the policies which will transform Britain and redistribute power and wealth away from the few to the many.”

He was speaking at a community centre in Liverpool, where Momentum is holding a four-day “festival of arts and culture” running alongside Labour’s annual conference.

Dubbed “The World Transformed”, the event is intended to promote political discussion and will include talks, art exhibitions and workshops, including a banner-making class for children.

– ‘Enormous upsurge’ –

On the eve of the leadership announcement, young activists moved through the festival venue putting up banners, fixing temporary walls and setting out chairs, all of them volunteers.

Corbyn’s election as leader enthused many people, and Labour party membership has more than doubled to 550,000 in the past 18 months. Momentum claims it is simply trying to harness that energy.

Across Europe, “what we were seeing is the stagnation or demise of social democratic parties”, Schneider said.

“What we’ve got with the Labour party is the traditional party which has this enormous upsurge, which has the capacity to tap into this feeling for slightly more radical politics.”

Saying Momentum is about more than one person, supporters claim Corbyn can win the next general election in 2020, despite poor personal poll ratings.

“As a party we’re one of the largest in Europe, with over 500,000 members and I don’t believe there isn’t anything that that that group of people can’t sort out,” said 28-year-old activist Roland Singer-Kingsmith, 28.