Anti-academy protesters are appealing a High Court ruling that the Government is not breaking European Union laws in the way it appoints school sponsors.
Parents in north London launched the landmark legal battle in November, claiming that the way academy sponsors are selected breaks EU competition and procurement rules. They were seeking to overhaul the system to force local authorities to hold open competitions when choosing sponsors.
Separate judicial reviews against Ed Balls, the Schools Secretary, and Camden Council were brought by Gillian Chandler, a parent, following the council's decision to open an academy backed by University College London.
Mr Justice Forbes dismissed the claim last week, saying academies were free to operate outside the control of EU procurement rules.
He said he was satisfied that the council had not been biased in choosing UCL as sponsor and that it had made a rational choice not to hold a competition.
"The council considered that to hold a competition would create uncertainty and delay and would leave the council with less control over the process, and it therefore chose not to go down that route," the judge said.
Ms Chandler said she was angry at the judge's decision; the appeal was lodged on Monday.
"Camden did not give us enough information about what they were planning and how they chose the sponsor," she said. "We did not have a choice. It was done by the backdoor.
"Huge amounts of money are being spent on new academies, but it would be better spent on the schools we already have."
The opening of the UCL academy has been dogged by controversy, including a protest by some lecturers from the university who believe that sponsorship could damage links with other schools.
Lawyers for Ms Chandler argued that academy sponsors gain a commercial advantage by increasing their public profile, and so selection should be made more transparent.
Campaigners claim that decisions are often made behind closed doors, meaning they lack scrutiny and deny the chance for other types of schools to be opened.
It is understood that the Camden court case made some academy sponsors cautious about progressing with plans for new schools.
Sponsors who had been selected but had not yet signed off their funding agreements were concerned that if the case had gone against the Government their plans could have been sent back to the drawing board, costing them both time and money.
Government rules state that there must be a competition when a new school opens so that different organisations, including local authorities, businesses and charities, can bid to run it. But academies are exempt, leading opponents of the programme to claim that the semi-independent schools have an unfair advantage.
Mr Balls and Camden Council welcomed the High Court decision, saying they had been fully vindicated. "We will continue to ensure that all our systems are geared towards transforming standards in our most challenging schools," Mr Balls said. "And we will continue to make this happen in an open, fair and efficient way."