About 25,000 staff who are currently “unqualified” would also be fully trained during Labour’s first term in office if the party won the 12 December general election, the party insisted.
Under new plans to improve education standards, Labour has also promised £7bn to tackle overdue repairs and install safety measures, like sprinklers.
The announcement follows a global study which found British teenagers were among the least satisfied with their lives.
Labour says it will “close the gap” in funding for pupils with special educational needs and it will ensure “every child is taught by a qualified teacher” in a safe building.
Education experts have welcomed extra funding – but the headteachers’ union said Labour’s pledge to recruit 20,000 new teachers was still not enough to keep up with pupil numbers.
Just last week, new figures revealed that the government had failed to hit targets for recruiting secondary teachers for the seventh consecutive year at a time when pupil numbers are rising.
Paul Whiteman, general secretary of school leaders’ union NAHT, said: “We need significantly more recruits than Labour are suggesting just to meet rising demand, never mind reduce current class sizes.
“The new recruits we need will not magically appear, and nor will they stay if we don’t also address the stress and unnecessary workload that is widespread in the system.”
Announcing the party’s plans on Thursday, Angela Rayner, shadow education secretary, said: “Labour will transform education standards in this country for every child, capping class sizes and ensuring every child is taught by a qualified teacher in a safe school building.
“We will invest in record per-pupil funding, restore the pupil premium and close the gap in support for children with special educational needs and disabilities, to give every child the support they need.”
She added: “The Tories cannot be trusted to do this. They have slashed school funding for the first time in a generation, leaving pupils taught by unqualified teachers, crammed in to super-sized classes, and not receiving the support they need.”
On the announcement from Labour, schools minister Nick Gibb said: “Conservative education reforms are improving standards in our schools, meaning children can get a better start in life.”
He added: “The Conservatives will get Brexit done so we can move on and focus on continuing to raise school standards whilst increasing funding for every school in the country.
“Corbyn’s Labour would wreck the economy, leaving no money for public services, and would waste the whole of next year on two chaotic referendums.”