Academies pose serious problems for local authorities and schools, it has been claimed.
Alasdair Smith, national secretary of the Anti-Academies Alliance, suggested that they have a negative impact on other schools in their area.
"I do think it takes funding away from local schools because they take part of the money left over from the direct schools grant, which is money that is given by the government to local authorities which is then passed on to the school," he explained.
"But the local authorities hold part of that money back and what is happening is a percentage of that money is being given to the academy on a pro-rata basis proportionate to how many people they have, not according to the need.
"This means that local councils are losing money for their essential services which is causing their essential services to decline. There is also another mechanism which means the government is top-slicing money from all council budgets to pay for academies."
This means the whole council is losing money to academies and not just from the education budget, Mr Smith added.
Speaking last year, Dr Mary Bousted of the Association of Teachers and Lecturers said the government's plans to encourage more schools to convert to academy status are "irresponsible" and not properly thought through.