The policy, unveiled ahead of the Conservative Party conference in Birmingham, would remove the current limit that cuts off 30 hours a week of free childcare for families where one parent earns more than £100,000, regardless of the other parent's salary. Under the proposal, all parents working 16 or more hours a week would be eligible.
Party leader Kemi Badenoch said the current system was "absurd" and a disincentive to work more. "I'm a mum-of-three and I've had to make the same choices many families have had to make on work and childcare," she said. "No one should be turning down a promotion or a pay rise because they literally cannot afford to earn more." Badenoch argued the policy would particularly help women, who often carry more childcare responsibility.
The Conservatives say the £700m annual cost would be offset by cutting jobs at organisations such as Arts Council England and the Environment Agency.
A Labour spokesperson said: "It tells you everything you need to know about the Tories that the first of their own tax policies they want to unpick is one helping higher earners. They clearly don't want to admit that they set the thresholds in the first place."
The childcare announcement follows last year's Conservative conference pledge to abolish stamp duty on primary residences in England and Northern Ireland, a £9bn a year tax cut that would disproportionately benefit wealthier households.
The party also outlined a plan to build 50,000 new prison spaces in England and Wales, a 50% expansion in capacity. This would be partly funded by slashing overseas aid to £1bn a year, a 90% cut on current plans. Aid groups have previously warned such a reduction would not cover existing contributions to international bodies, damaging Britain's global influence.