The death knell of the maintained school will be sounded today by the Chancellor who will announce they will all be turned into academies by 2022.

George Osborne will use today's budget to unveil a £1.5bn plan which will also pave the way for a quarter of secondary schools to provide an extra five hours each week of lessons, or extra-curricular activities such as sport and art, in a move he claims will 'signal the end to the Victorian tradition of the school day finishing at 3.30pm'.

Norfolk currently has 308 out of its 423 schools which are not academies or free schools. In Suffolk there are 237 out of 326 which stand to be converted, while in Cambridgeshire 182 of its 257 schools are not yet academies.

The announcement is likely to meet opposition. The government is already struggling to find enough private sponsors to run the institutions, and it comes after the government's chief inspector Sir Michael Wilshaw claimed that multi-academy trusts had 'manifested the same weaknesses' as the worst-performing local authorities and 'offered the same excuses'.

But Mr Osborne will press ahead with plans pledging to 'put the next generation first' as he announces that schools will either have to have converted by 2020 or have an academy order in place by then, so that they are committed to converting by 2022.

For any school that fails to have a plan in place, the government will take on radical new powers to intervene and ensure academy conversion takes place.

He said: 'The Budget I'll deliver today will put the next generation first. And at its heart will be a bold plan to make sure that every child gets the best start in life.

'It is simply unacceptable that Britain continues to sit too low down the global league tables for education. So I'm going to get on with finishing the job we started five years ago, to drive up standards and set schools free from the shackles of local bureaucracy.

'I also want to support secondary schools that want to offer their pupils longer school days with more extra-curricular activities like sport and art. So we'll fund longer school days for at least 25 per cent of all secondary schools.

'Now is the time us to make the bold decisions and the big investments that will help the next generation, and that is what my Budget today will do.'