Jeremy Corbyn has accused the Government of causing a "crisis in our schools" at a speech to a teaching union.
The Labour leader entered National Union of Teachers's (NUT) conference in Brighton to a standing ovation, and he told delegated the Government's push for academies and free schools would lead to the "asset -stripping of our education system".
His speech comes more than a decade after senior Labour figures stopped appearing regularly at the gathering following the hostile reception given to then-education secretary Baroness Estelle Morris.
The Government's plans to force all schools in England to turn into academies have come under fire from Labour, the unions and Conservatives in local government who will be stripped of the power to run schools in their areas.
George Osborne used the Budget to announce the forced academisation of all schools. This is an ideological attack on teachers and on local and parental accountability - an attack which was nowhere in their manifesto at the last general election. The Tories want to shut parents out of a say in how their children's schools are run. I want schools accountable to their parents and their communities - not to those pushing to be first in line for the asset-stripping of our education system.
He said "there is a crisis in our schools now" with increasing class sizes, teacher shortages and a school places crisis for parents.
"The forced academisation will do nothing to address any of those problems. And yet £700 million will need to be found to fund this needless reorganisation," he added.
He was given a much warmer welcome than Lady Morris, who was heckled and slow hand clapped by delegates in 2002 when she was the last Labour education secretary to speak at an NUT conference.
Afterwards she said: "If I told them that tomorrow was Sunday, I think they'd say it wasn't and pass a motion against it."
Schools minister Nick Gibb said it was "disappointing but not surprising" that Labour is opposing education reforms over the last five years.
Their plans would reverse the remarkable rise in standards across England’s schools since 2010, which has seen 1.4 million more young people in schools rated good or outstanding, and see a return to the days of declining standards, poor school discipline and low aspiration that typified the last Labour government’s attitude to education. While Jeremy Corbyn and Lucy Powell are willing to undo the academisation process which started under Tony Blair and Andrew Adonis, we are determined to create a dynamic school-led system which empowers pupils, parents and school leaders.