The academies policy has been arguably the most significant educational reform of recent years, with more than 4,000 schools enticed to make the switch by the promise of increased freedom and flexibility.

But sixth-form colleges claim that, having been “starved into the academies camp” by funding cuts, they are now effectively being barred from conversion. The Department for Education (DfE) has refused to publish guidance on how colleges can become academies and no procedure has yet been drawn up that would allow the institutions to alter their legal status.

Earlier this year, representatives from the Association of Colleges met schools minister Lord Nash to discuss the matter, only to be told that the government had ruled it out. Mark Bramwell, AoC associate director of sixth-form colleges, said: “We were told that there was no legal process for sixth-form colleges converting to academy status.

“We would need to have a whole new procedure and it would take a long time for conversion to happen. But [ministers] can’t just say no. We’ve taken legal advice and there’s no reason colleges can’t apply. No one can rule it out; legally it is possible.”

TES understands that two colleges have taken legal advice about the possibility of forcing through academy conversion to help improve their financial standing, but currently have no plans to pursue this.

Unlike their counterparts in schools, college principals already enjoy significant autonomy. Several studies, not least a 2011 report by the National Audit Office, argue that colleges outstrip schools on most measures of performance.

Several factors, though, have conspired to prompt colleges to cast envious glances at the schools sector. A report published last month by consultancy London Economics shows that academies can access pound;1,598 (35 per cent) more funding per student than colleges.

Furthermore, colleges claim they are doubly penalised because they are unable to cross-subsidise post-16 provision with pre-16 funding and have to pay additional VAT costs, equating to pound;200,000-300,000 per year for an average-sized college.

Mr Bramwell said some principals also felt marginalised by the government’s political focus on academies and free schools. “They want to be swimming with them in the mainstream. But my view is that colleges have been incredibly autonomous since 1993, and some might find it difficult to readjust to more [centralised] planning and coordination in the schools sector.”

Members of the Sixth Form Colleges’ Association (SFCA) considered mass academy conversion in 2012, but eventually decided against the move. However, with the government having made it explicitly clear that no change in the tax rules for colleges would be forthcoming, SFCA deputy chief executive James Kewin told TES that the prospect of academy conversion had again emerged.

“Given that they have faced deeper funding cuts than any other group of providers, it is hardly surprising that some sixth-form colleges have considered converting to academies,” Mr Kewin said. “In effect, sixth-form colleges are being starved into the academies camp, but when they arrive at the gate they are now being told that they are not allowed in. We have one or two colleges that may challenge this decision, particularly as independent schools have been allowed to convert.

“We would much rather that sixth-form colleges were treated fairly in their current guise rather than changing their status to become academies. But in desperate times, we understand their motivation. It is odd that the government is preventing them from joining the education programme that is supposed to be the key to transforming our education system.”

A DfE spokesperson said that as sixth-form colleges already enjoyed similar autonomy to academies, the department had no plans to publish guidance for sixth forms that wished to convert. “We have ended the historic unfair funding difference between post-16 schools and colleges by putting both on the same rate. We have also implemented recommendations that funding should be on a fair per-student basis, not per qualification.”