Free childcare: Welsh Conservatives' 30-hour pledge
The Conservatives are the latest party in Wales to promise to treble free childcare from 10 to 30 hours a week if they win the assembly election.
Shadow Education Minister Angela Burns said it would help parents return to work and boost the economy.
The Tories did not say how many weeks of the year their pledge covered. The Lib Dems have yet to reveal a plan.
"It is currently very difficult for working parents to take advantage of just 10 hours of free childcare, especially as provision frequently has to spread over five days," Ms Burns said.
"Welsh Conservatives will work towards trebling free childcare for working parents to help parents return to work so they can provide for their family and help deliver a stronger economy."
The Tories claimed Wales risked falling behind England, where the UK government has promised to double free childcare for parents of three and four-year-olds from 15 to 30 hours a week.
They are currently allowed 570 hours of free early education or childcare per year, usually taken as 15 hours a week for 38 weeks.
Prime Minister David Cameron has said the promise to double it - originally due to take effect in 2015 - would now be fully implemented by 2017.
However, a report for the Welsh government in February said increasing free childcare would make little difference in terms of reducing poverty or getting more women into work.
The Welsh Liberal Democrats said they planned to unveil their childcare policies later in March.
A UKIP spokeswoman said: "We support extending free childcare, if it can be paid for, but the problem is lack of availability in Wales.
"Fewer free hours are available and largely only in schools and often during term-time.
"We would increase the supply of childcare by allowing child minders to work without needing to get regulatory approval."
Meanwhile, a survey of childcare providers in Wales suggests many are struggling due to increasing costs and fewer children taking up places.
Nearly a quarter of those responding to the National Day Nurseries Association (NDNA)'s annual survey said they had very little confidence about the future of their business.
NDNA chief executive Purnima Tanuku said the new National Living Wage would increase staff costs by 13% this year and 35% by 2019.
"This, coupled with chronic underfunding for free places and declining numbers of children attending, is causing real problems," she said.
The survey included 115 respondents from Wales, representing nearly a fifth of full day care providers here.