Jeremy Corbyn has today ridiculed David Cameron’s attempts at EU renegotiation as a “theatrical sideshow”, as he set out the areas in which he believes the European Union needs to change.

The Labour leader was speaking at a meeting of the Party of European Socialists (PES) in Brussels, and took the opportunity to attack the proposed ’emergency brake’ on EU migrants’ benefits as “irrelevant”.

He said the brake would not do anything to address the problem of British workers’ wages being undercut and that Cameron’s aim was to appease parts of his own party rather than getting a better deal for the UK.

“The negotiations David Cameron is conducting on Britain’s relationship with the European Union are a theatrical sideshow, designed to appease his opponents within the Conservative Party. They are not about delivering reforms that would make the EU work better for working people,” Corbyn told the meeting of PES, of which the UK Labour Party is a member.

He also reaffirmed his commitment to campaign for a Remain vote in the referendum, saying that membership brings with it investment, jobs and workers’ rights – and said that nothing in Cameron’s negotiation will make him change his view.

Corbyn said: “The Labour Party will campaign to keep Britain in Europe in the forthcoming referendum, regardless of the outcome of the talks being held in Brussels today. That is because it brings investment, jobs and protection for British workers and consumers.

“David Cameron’s misnamed ’emergency brake’ on migrants’ in-work benefits is largely irrelevant to the problems it is supposed to address. There is no evidence that it will act as a brake on inward migration. And it won’t put a penny in the pockets of workers in Britain or stop the undercutting of UK wages by the exploitation of migrant workers.”

Corbyn has long criticised areas of the EU but has been more reserved about those views since he initially came under pressure and subsequently agreed to commit Labour to campaigning for a Remain vote.

Yet today he outlined how he wants to see the EU change, including improving democratic accountability and stopping forced privatisation of public services.

“David Cameron’s negotiations are a missed opportunity to make the case for the real reforms the EU needs: democratisation, stronger workers’ rights, an end to austerity, and a halt to the enforced privatisation of public services,” he said.