Every school in England could be turned into an academy under plans expected to be laid out in the Budget.

The controversial reform could be set out in draft legislation as soon as Thursday, the BBC reported.

It follows a pre-election pledge by David Cameron that would switch the status of all state schools – both primary and secondary – regardless of the local appetite for the changes.

Academy schools are independent of local authority control and the academy’s sponsor is in charge of improving standards. Sponsors can be businesses, universities, other schools, faith groups or voluntary groups.

The introduction of academies by Tony Blair and Andrew Adonis – the then PM’s education advisor – proved a lightning rod for criticism from some parts of the Labour Party, as well as teachers, when they began to be introduced from 2002.

Blair opened academies as a way of tackling failing schools. The structure was designed so that large changes could be implemented quickly. However, the blueprint was never intended to fit all schools.

When David Cameron entered Downing Street he became an enthusiastic advocate for extending the academies programme.

Michael Gove, the Tory Education Secretary for much of the last parliament, allowed schools to convert to academies and attached financial incentives to do so while Education Secretary.

The schools do not have to follow the national curriculum, term times or rules on admissions or exclusions. Oversight of schools falls to the schools’ sponsors or national Government.

More recently Labour has criticised the academy structure for failing to provide enough school places because there is no mechanism by which schools places are matched to local need. Schools are built wherever sponsors can be found.

Lucy Powell, Labour’s Shadow Education Secretary, has attacked the extension of academies for failing to bring improvements in education and for causing schools to be vastly over capacity.