Speaking to senior union leaders at a TUC dinner in Brighton, he claimed the Prime Minister will be forced into a U-turn.
“The education system illustrates the very real divide between Labour and the Tories,” Mr Corbyn told guests at the TUC general council dinner.
“We have a deeply ideological Prime Minister pushing for the expansion of grammar schools.
“Just as we turned them back on forced academisation, together we will defeat their plans on grammar schools.”
In May this year, the then Education Secretary Nicky Morgan announced that the Government was abandoning its controversial scheme to force schools to convert to academy status,
The climbdown came with David Cameron facing the threat of a humiliating Commons defeat, after Tory MPs savaged the plans during an Opposition Day debate staged by Labour.
The new Prime Minister’s grammar schools are also likely to face a Tory rebellion in the Commons, led by former Education Secretary Ms Morgan, who was sacked by Mrs May in July.
And even if the proposals are approved in the Commons, they face an uphill battle in the Lords, where the Conservatives do not have a majority.
Labour’s leader in the Lords, Baroness Smith, has already claimed Labour, LibDem, Crossbench and some Tory peers will join forces to defeat them.
In his TUC speech, Mr Corbyn also says: “This is a Prime Minister who claims to be for the many, not the privileged few – a Prime Minister who voted for the bedroom tax, voted for the Trade Union Bill and now wants to segregate children at 11 years old.
“But while she’s restoring grammar schools, she’s doing nothing about the cut in the schools budget, nothing about the teacher shortage, and nothing about rising class sizes.
“This isn’t a matter just for the education unions – many of your members are parents, and we all have a stake in ensuring no child is left behind – that we have an education system and an economy that works for everyone.”They are the values that guide us: unity and universality, not division and privilege.”
News Source SkyNews