The UK faces the threat of a resurgent far-right at the forthcoming European elections, Jeremy Corbyn will warn, as he blames government cuts for opening the door to demagogues.

The Labour leader will seek to portray the campaign as one against extremist forces looking to infiltrate communities left feeling neglected, as he faces criticism from some of his own MPs that, under his leadership, the party has failed to attract support by equivocating on Brexit.

“Years of neglect of our communities has opened the door to the far right. It’s up to Labour to stand up to that threat,” Corbyn will tell a rally in Bootle, in Merseyside on Saturday. “That means rejecting the failed economic system and giving people a real alternative that unites the many against the entrenched power of the few at the top.”

His appeal comes after Labour ended cross-party talks with the government aimed at reaching a compromise Brexit deal. It also follows criticism from some Labour MPs that the party has been trying to face both ways on Brexit, with a confused message over the circumstances in which it would back a second referendum.

The leadership is sticking to a conference motion committing Labour only to keeping open the option of a public vote on Brexit if the party cannot secure a general election.

Among the MPs calling for a harder line is Clive Lewis, who described Labour as being “skewered on a harpoon of paralysis and indecision”. Jess Phillips has said the party’s position has failed and that “bravery is needed”, while Owen Smith has said Labour’s “Brexit fudge” was “melting under the public’s gaze”.

Seeking to shift the focus of the conversation to the government’s record and the threat of the far-right, Corbyn will say: “Divisions in our society existed before the EU referendum, they are not new.

“If the government pays for tax cuts for the richest by cutting vital public services, it drives inequality between the many and the few. And it’s in that space that the far right can prosper.

“Labour’s mission is to unite working class communities in all their diversity around solutions to the problems they face, instead of looking for scapegoats.”

He will warn that the far-right would not take on the “bankers, the tax dodgers and the big polluters”, nor would such parties “invest in our communities, make the wealthy pay their fair share, end insecure work or boost people’s wages”.

And Corbyn will denounce “politics as usual”, saying it will be ineffective in those communities hardest hit by government cuts. “We need Labour’s radical programme to transform our country and turn the tide of inequality by ending austerity and investing in our communities and people. We offer hope, the far right offers only fear.”

Nick Lowles, the chief executive of Hope not Hate, said he feared the Brexit party would triumph in the European elections: “The polls suggest a shocking win for a populist party whose leadership has been rocked by racism scandals, tapping in to a dangerous anti-politics mood while scapegoating and offering simplistic answers. No one should run the risk of regretting sitting this election out or letting extremism creep in through the back door.”