The Scottish Government has been criticised after admitting it was failing to reach childcare provision targets.
Forecasts show 8,707 two-year-olds will be taking up their entitlement to 600 hours of funded early learning and childcare (ELC) by April 2021.
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That represents around 60% of the estimated eligible population, while in England it is already 70%.
The figures were revealed during a range of parliamentary questions submitted by the Scottish Liberal Democrats, with the party's education spokeswoman now calling on the Scottish Government to "double down" on its efforts.
Beatrice Wishart said: "All of these shortfalls are jeopardising our ability to make real progress in closing the poverty-related attainment gap.
"High-quality childcare provision is essential to giving all young people the best start in life.
"The minister for childcare should be royally embarrassed that this flagship policy is being so poorly mismanaged it won't even bring us up to speed with the rest of the UK by 2021.
"We are years into this policy so the problems it's having identifying which two-year-olds are eligible for free childcare should have been prioritised long ago.
"The Scottish Government has made a promise to parents.
"They need to face up to the situation they are in and double down on recruitment efforts if they're going to make that reality."
The questions also revealed that the Scottish Government's August 2018 target to recruit 435 additional graduates to nurseries in the most deprived areas is still being missed, with only 92% of these positions having been filled more than a year later.
A spokesman for Minister for Children and Young People, Maree Todd, said: "This ludicrous press release from the Lib Dems completely ignores the fact that from August next year - never mind 2021 - we will be making available 1140 hours per of childcare to all three and four-year-olds and eligible two-year-olds.
"This is far more ambitious than what is available south of the border.
"In terms of reaching out to families of eligible two-year-olds, it is well known that we require the UK Government to pass legislation so that Scottish councils can access the same data as councils in England. They have recently agreed to do so - and we now need to see this delivered as soon as possible.
"Thousands of children across Scotland are already benefiting from improved childcare provision - and just for once the Lib Dems might have the courtesy to acknowledge the hard work of all those involved across national government, local government and our partners in getting us this far."