A HIGH court judge has granted permission for a judicial review of plans for an incinerator on the border of Croydon and Sutton.
Judge Justice Collins ruled that the case made by campaigners is "arguable", adding that there was a potential conflict of interest between Sutton Council and developers Viridor.
The case will now be heard in full later this year.
Shasha Khan challenged last year's decision to approve plans for the Beddington Lane plant on the basis that Sutton applied the wrong planning policy and the authority was "unduly influenced by their contractual relationship with Viridor".
The incinerator is backed by the South London Waste Partnership, which comprises Croydon, Sutton, Kingston and Merton councils.
It would replace an existing landfill site and would burn around 275,000 tonnes of rubbish a year to create energy. The Stop the Incinerator Campaign argues that it presents a serious health risk.
The incinerator was given planning permission by Sutton Council - a decision later ratified by the Mayor of London - despite the site being on protected Metropolitan Open Land.
Judge Justice Collins made his ruling at the High Court on Friday.
Mr Khan said: "I am so grateful for the hundreds of small donations to finance this case from members of the public like me who want parks for their kids, not waste incinerators.
"In World Cup terms, a tricky qualification has been achieved and now we all look forward to the finals."
Sue Willman, from Deighton Pierce Glynn, representing Mr Khan, said: "Despite powerful opposition by council and developers, a senior planning court judge has recognised the strength of the case not to grant permission to burn waste on a site which is a haven for wildlife and migrating birds."
Mr Khan, a prominent member of Croydon Green Party, has taken sole responsibility for the legal challenge, which could cost up to £35,000.
Croydon Labour Party, which last month retook control of Croydon Council, is opposed to the incinerator.
Stuart Collins, cabinet member for Clean Green Croydon, said the council would be following the judicial review closely.
He added: "We need to wait to see what happens and then, if the case is won, that will be the time to talk about alternative technologies.
"If the case is lost then our main concern is to look at the strictest health and safety monitoring on that site."
Sutton Council and Viridor have yet to comment on the ruling.
