Labour MP Jon Cruddas’s fight against proposals for a 2,000-inmate prison on the Dagenham/Rainham border has seen a glimmer of success.

The Greater London Authority informed the Dagenham and Rainham MP last week that they are now against the proposed site at Beam Park.

Mr Cruddas said: “They are worried about resistance locally. This is major progress and a sign that the campaign is having an effect.”

But he warned that the battle is far from over and said the government seemed “determined” to build the facility.

“We still have to convince the Ministry of Justice. They are still, to my knowledge, very keen on Beam Park.

“They want prisoners to be closer to home and want more prisons in the London area. They also want to move prisons out of central London into outer London. Both of which suggests that we are still very much in their sights,” he said.

Three years ago similar plans for a slightly smaller prison at Beam Park were thrown out following a strong campaign led by Mr Cruddas, who presented a 15,000-signature petition to No 10.

But in April this year Barking and Dagenham Council got wind of new plans that indicated the site was “one of very few in London” being considered for a what could become Britain’s largest jail.

Mr Cruddas has reignited his crusade and on Saturday is organising a rally to build the momentum, taking place at Rainham Villlage Primary School from 10am.

He said: “We are going to have rallies and events across the constituency to try and test opinion and build involvement.

“I will be calling debates in Parliament and building a long-term campaign, as I don’t think the issue will go away soon.”