Corbyn used his speech at the annual Labour Party Conference to set out plans for 30 hours of high-quality, "genuinely" free childcare to be available to all two-, three- and four-year-olds, with no means testing.
Currently 30 hours of free childcare is available to disadvantaged two-year-olds, as well as three- and four-year-olds whose parents are in work and earning within certain limits. There are also concerns that 30 hours provision is not genuinely free because providers are not being funded adequately and are charging parents additional costs to try to make ends meet.
"Patchy support for childcare is holding back too many parents and families," Corbyn said.
"Universal free high-quality childcare will benefit parents, families and children across our country. It is a vital and long overdue change that will transform people's lives and meet the needs of a 21st century Britain for all."
In addition to extending 30 hours entitlement, Corbyn also announced plans to provide additional subsided hours of childcare on top of the free 30 hour allowance.
These additional hours will be free for those on the lowest incomes and, for those on the highest incomes, they will be offered for no more than £4 per hour.
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Corbyn also outlined plans to raise standards of childcare by introducing a two-term plan to shift to a graduate-led workforce. This will be designed to improve the pay and skill levels of childcare staff, drive up standards to improve our children's life chances and close the attainment gap.
"Opportunity matters most in the earliest years of life," Corbyn said.
"It is a crucial time to open up children's life chances. Driving up standards of childcare will make that vital difference for millions of our children."
Part of Labour's plans will involve simplifying the childcare system for parents, by launching a national childcare access portal online. It said the improved, simplified system will replace the current arrangement of vouchers and credits.
Purnima Tanuku, chief executive of National Day Nurseries Association, said Corbyn has recognised what many in the sector have been saying about the current system, that it is not free for either parents or providers.
"While many nurseries would welcome this level of investment and proposed hourly funding rate, the sector is largely made up of private, voluntary or independent nurseries. These tailor their business model to satisfy local, parental demand. The funding must keep up with rising costs of delivery that increase year on year.
"The correct level of funding for all these providers must be there from day one for this ambitious scheme to work. If Labour doesn't get this right then they risks more nurseries folding under the cost pressures of such a large scale plan which will mean parents being unable to access the offer."
Tanaku said she also welcomes the plans to adopt NDNA's recommendation for a "childcare passport", to streamline all childcare support into one online account for each child.
She added that plans for a graduate-led workforce and for all staff to be qualified to or working towards Level 3 qualifications would support quality early learning for all children, help to close the attainment gap, and improve social mobility.
"But all this costs money. Labour would need to work closely with the sector and invest sufficient money for this to work," she said.
Neil Leitch, chief executive of the Pre-school Learning Alliance, said: "We know how important childcare and early education are to ensuring that all children are given the best possible start in life, and that it's those children from the most disadvantaged backgrounds who have the most to gain from access to quality early learning experiences.
"As such, Labour's pledge to provide additional financial support to the lowest-income families is, in theory, a welcome policy.
"Similarly, with early years providers having been overworked and underpaid for far too long, a plan to not just encourage but also financially support the development of a graduate-led workforce by delivering improved wages and a new national early years payscale is very positive in principle.
"That said, put together, Labour's ambitious proposals - extending the so-called free entitlement and introducing subsidised care for all with seemingly no upper earning limit on eligibility, increasing funding rates to £7.35 per hour, and overhauling the childcare payment system - would be, to put mildly, incredibly costly.
"As such, as a sector that has all too often been on the end of improperly costed and inadequately funded pledges, many childcare providers will be understandably sceptical as to how all these proposals can collectively be delivered as outlined, even over an extended period of time."
Liz Bayram, chief executive of the Professional Association for Childcare and Early Years (Pacey), said: "Pacey welcomes the Labour Party's commitment to childcare and early years, and recognition of the central role it has on children's life chances. However, it is absolutely vital that all childcare entitlements, both new and existing, are properly funded, or the entire sustainability of the childcare and early years sector - and the quality of provision - will be placed further at risk.
"It is encouraging that Jeremy Corbyn has recognised that the current system is underfunded and ‘free in name only'. We invite the Labour Party to work collaboratively and constructively with the sector to ensure there is a workable and sustainable delivery plan for their proposals."
Ryan Shorthouse, director of think tank Bright Blue, said: "The primary purpose of formal childcare is to care for and educate children. A wealth of evidence suggests that formal childcare is the most important part of the education system.
"The priority for additional public funding on childcare, therefore, should be on improving staff quality and building a graduate-led workforce, rather than increasing the free hours available to parents through the early years free entitlement.
"The evidence is clear: there are no gains to child development from being in formal childcare for more than 15 hours a week. If parents are struggling with childcare fees, they should have the opportunity to take out government-backed, income-contingent loans to smooth the costs they face over a long period. This would make childcare affordable for all families overnight."
