Every state school in England will become an academy by 2022, with £1.5billion of additional funding for education in the Budget, Chancellor George Osborne will announce today.
The cash will also allow some secondaries to offer a longer school day, remaining open after the traditional "home time bell" at 3.30pm for five hours or more a week of additional lessons or extracurricular activities.
But the plan has come under fire from teaching unions, with the National Union of Teachers accusing the Chancellor of "undoing over 50 years of comprehensive public education at a stroke".
Mounting concern about the global economy will cast its shadow over Mr Osborne's eighth Budget, with the Chancellor planning to impose a further £4 billion of spending cuts to allow him to meet his fiscal target of getting the nation's finances into surplus by the next election.
The Financial Times reported that he will be forced to admit he has missed one target to cut Britain's debt as a share of GDP this year.
The Chancellor has blamed uncertainty over the prospects of China and the eurozone for dispelling the sunny mood of the Autumn Statement four months ago, when he said that higher-than-expected tax receipts would allow him to avoid cuts.
All eyes will be focused on whether Mr Osborne hikes fuel duty for the first time in five years - raising £1 billion for every 2p on a litre at the pumps - despite pressure from Conservative MPs to hold back. He has already buckled to backbench protests by ditching a mooted plan to reform tax relief on pensions
And there is speculation that he will nudge up insurance premium tax, while charity Scope said disabled people were "anxiously awaiting" the Budget statement amid concerns they may face further cuts to their benefits.
Already trailed ahead of the Budget is a £300 million package of investment in transport infrastructure in the North of England - including a green light for the HS3 plan to improve east-west rail links - as well as £80 million to take forward planning for the £27 billion Crossrail 2 north-south train line through London.
Mr Osborne is also expected to confirm plans for a new £1.2 billion fund to release brownfield land for 30,000 new starter homes, as well as trials of driverless cars on British motorways, and he will confirm plans to crack down on the abuse of personal services companies by public sector workers seeking to minimise their tax bills.
More than 4,000 schools have already taken on academy status, freeing them from local authority control and giving head teachers and governors more power over discipline, curriculums and budgets. The Conservative manifesto for last year's general election promised to extend the status to all coasting and failing schools, and Prime Minister David Cameron last autumn set the ambition to make every state school an academy.
Mr Osborne will set out plans to require every school in England to either convert to academy status by 2020 or to have a plan in place by that date to do so by 2022. New powers will allow the Government to intervene in any school which fails to draw up a plan to ensure that academy conversion takes place.
Schools will be able to bid for new flexibility to tailor the structure and duration of their school day to suit their pupils' needs. At least a quarter of secondaries will be given funding to provide at least an additional five hours a week of lessons and activities including sports and art.
In total, Mr Osborne will announce more than £1.5 billion in additional funding to drive up standards in education over the course of the current parliament. The cash comes on top of decisions at November's Spending Review to protect the schools budget in real terms and increase total financial support for education by over £10 billion a year by 2019/20.
Mr Osborne 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 extracurricular activities like sport and art. So we'll fund longer school days for at least 25% of all secondary schools.
"Now is the time for 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."
Responding to press speculation of an announcement on academy schools, NUT deputy general secretary Kevin Courtney said: "Parents will be as outraged as teachers that the Government can undo over 50 years of comprehensive public education at a stroke."
Mr Courtney said a range of evidence showed that "academy status not only does not result in higher attainment but that many chains are badly failing their pupils, particularly their disadvantaged pupils".
He added: "The Government's ultimate agenda is the privatisation of education withschools run for profit. The NUT will continue to resist the Government's attempts to privatise our education system and will campaign alongside parents and other allies to Stand Up for Education."
For Labour, shadow education secretary Lucy Powell accused ministers of ignoring a warning by the Chief Inspector of Schools Sir Michael Wilshaw highlighting "serious weaknesses" in academy chains.
"How the Government can plough ahead with the wholesale academisation of all schoolsin light of his evidence beggars belief. We want to see robust accountability and oversight of all schools regardless of type," she said.
"It's about time the Government came forward with a comprehensive plan for school improvement for all children, in all schools up and down the country, and a serious strategy for raising standards for the next generation."