The 30-hour free childcare entitlement for three- and four-year-olds, up from the current 15 hours a week, is due to be introduced from September this year.
Disadvantaged two-year-olds are currently eligible for 15 hours of free childcare each week, but a leaked draft version of Labour's manifesto suggests the party is keen to extend this so that all two-year-olds are eligible for 30 hours of childcare each week.
As part of a five-point plan for childcare, the document confirms that Labour will "maintain current commitments" to providing 30 hours of free childcare for three- and four-year-olds from September, and will "make significant capital investment" during the first two years of government to ensure that there are enough places to meet demand.
In addition to this, it reveals that Labour would "extend the 30 free hours to all two-year-olds and move towards making some childcare available for one-year-olds".
Labour also intends to introduce subsidised provision on top of free entitlements, in order to ensure that "everyone has access to affordable childcare no matter their working pattern".
And it wants to change the system of subsidies being given directly to parents, who it says "often struggle to use them", replacing it with direct government subsidies.
The document also outlines plans to create a qualified, graduate-led workforce, by increasing staff wages and enhancing training opportunities.
"This will benefit staff, who are among our worst-paid workers, and improve child development," the document states.
Neil Leitch, chief executive of the Pre-school Learning Alliance said that although the pledge to extend the 30-hour offer to two-year-olds is likely to be welcomed by parents, it will be "incredibly costly" in light of the higher costs associated with delivering care for younger children.
"Add to that the suggestion of introducing additional subsidised provision on top of free entitlement hours, and it's clear that substantial investment into the sector would be needed to make these proposals work in reality," he said.
"Crucially, this investment would need to ensure a substantial increase in provider funding rates, and not just the capital investment referred to in the draft document.
"It is, of course, important to remember that this is a leaked, draft document and so the final manifesto may well look different. We hope that Labour - and all other political parties - engage fully with those working in the early years to ensure that any promises they make are in fact workable and deliverable in practice."
Purnima Tanuku, chief executive of National Day Nurseries Association, said: "While the Labour manifesto is a draft version, the sector will see pledges to offer more ‘free' nursery hours to a wider age range of children.
"We have sent a strong message to all the political parties calling for well-thought-out plans for early years, developed in consultation with the sector.
"Any pledges, current or future, including further expansion of funded places, need the right investment so that nurseries can be sustainable whilst delivering the high-quality childcare that children and families need."