Parents have failed to sign up for a scheme which entitles them to 30 hours of free childcare a week.
Dads and mums in Huddersfield and West Yorkshire had previously been eligible for 15 hours free child care per week.
But under a Conservative manifesto pledge working parents of children aged three and four are entitled to double that.
More than 200,000 parents have applied for the scheme, the deadline of which is tomorrow (August 31).
But according to the Mirror thousands of places remain unclaimed.
Parents applying for the scheme receive codes which, once they are validated, can be exchanged for free hours of childcare.
But a week before the deadline, the Department for Education admitted just 56% of codes had gone through the validation process.
That left 44% - estimated at 82,000 by the Observer - which were still to go through the Eligibility Checking System (ECS).
Neil Leitch, chief executive of nurseries' body the Pre-school Learning Alliance, said the figure was "incredibly concerning".
"We have long warned that inadequate government funding rates would lead to a reluctance among childcare providers to offer many, if any, 30 hour places," he said.
"Add to this the ongoing problems with the Childcare Service website, and it's clear that this is a policy coming apart at the seams.
"If the government wants the 30-hours to succeed, it simply must invest what's needed - both in terms of adequate funding rates and a robust IT infrastructure.
"If it doesn't, it's providers and parents who will be left short-changed."
The Department for Education admitted the figure in a letter on August 24.
It said all parents would get places if they apply by this Thursday, but it would take until "the second week of September" to process them.
The letter added it will be "at the providers' risk" if they choose to let children start before knowing if they're eligible.
The government was unable to update the 56% figure today but sources insisted more codes will have been processed by now.
An HM Revenue and Customs spokesman said: " More than 200,000 parents have successfully applied for a childcare account. We know that some parents and childcare providers have experienced difficulties accessing the service and we are sorry about the inconvenience.
"We’ve now made significant improvements based on customer feedback and on average more than 2,000 parents are applying successfully every single day.
"Those who apply in time and who get their code after 31 August will still be able to use it and the overwhelming majority – more than 200,000, have their codes already. Nobody need lose out as a result of the technical issues.
“Parents and providers experiencing difficulties or needing technical support can phone the childcare service helpline on 0300 123 4097.”
Tory Minister for Children and Families Robert Goodwill added: “We are determined to support as many families as possible with access to high-quality, affordable childcare, which is why we are investing a record £6 billion every year by 2020 in childcare – more than ever before – and doubling the free childcare available to working parents to 30 hours a week, saving them up to £5,000 a year per child.
“This funding includes an additional £1 billion per year by 2019-20 to pay for the free offers and to raise the national hourly rate to local authorities for three- and four-year-olds to £4.94 per hour. This is far higher than the average hourly cost of providing childcare for three- and four-year-olds, which recent research has found to be £3.72."
“Working” includes people who are in employment, are self-employed, and parents on zero hours contracts who meet the criteria.
Each parent - or sole parent in a one parent family - must earn the equivalent to 16 hours at the national minimum or living wage for the first three months after application.
The allowance does not apply to those who earn more than £100,000 a year.