The Education Secretary said early years education and childcare were her 'first priority' as she set out the Government's plans.
Bridget Phillipson has said extra childcare places in new school-based nurseries in England will be available to families from next year.
The Education Secretary said the early years was her "first priority" as she accused the Conservatives of leaving behind a "threadbare" childcare system.
The expansion of funded childcare for working parents - which was introduced by the Conservative government - began being rolled out in England in April.
Working parents of all children older than nine months are now able to access 15 hours of funded childcare, before the full roll-out of 30 hours a week to all eligible families in September 2025.
In its manifesto, Labour said it would open an additional 3,000 nurseries through "upgrading space" in primary schools, to deliver the extension of Government-funded hours families are entitled to.
Ms Phillipson told the Labour Party Conference: "Today I can tell you that change begins, delivery begins: those extra places start opening next year.
"The first phase of our new nurseries, of high-quality early education, boosting life chances for children and work choices for parents."
From next month, schools will be invited to bid for a share of GBP15 million capital funding, with capacity in the programme to deliver up to 300 new or expanded nurseries in this first round.
Schools will need to demonstrate how their proposals will respond to local demand, and funding will be allocated to successful schools in spring 2025 to support delivery for the first cohort of places.