Nicola Sturgeon insisted her government has delivered on its childcare pledge as she suggested Labour chiefs in Scotland's largest local authority were responsible for parents' frustrations.

The First Minister came under attack over the Scottish Government's commitment to provide 600 hours a year of free nursery care to all three and four-year-olds and some of the most vulnerable two-year-olds.

The policy was included in legislation passed exactly a year ago at Holyrood.

But Labour Scottish deputy leader Kezia Dugdale said parents in Glasgow were left frustrated because their youngsters could not get a funded place at the nursery of their choice or could not get care at times that suited their family.

She claimed that "on the SNP's watch things are getting worse for families trying to juggle family life".

While Ms Dugdale said the SNP leader was "celebrating the success" of the free childcare policy, she added: "She should try and celebrate it in front of parents in Glasgow, who are telling her there are thousands of children in Scotland unable to access the care her government gave them.

"She should look those parents in the eye and tell them they've never had it so good.

"They know it's not true. We know it's not true and I think actually the First Minister knows it's not true as well."

The Labour MSP continued: "Parents across Scotland have one simple question for the First Minister: isn't it about time she made good on her childcare promises?"

Ms Sturgeon, however, pointed to the role of Labour-controlled Glasgow City Council in childcare provision.

In heated exchanges at Holyrood, the First Minister said: "Tell you what I'm going to do right now, I'm going to look Kezia Dugdale in the eye and remind her who runs Glasgow City Council.

"If Kezia Dugdale has got issues with the delivery of the childcare policy in the city of Glasgow, I suggest she should make an appointment and speak to her Labour colleagues who run Glasgow City Council."

The First Minister said 98.5% of three and four-years-olds had registered for free nursery care under the scheme and added: "I did look parents in Glasgow who have frustrations about this in the eye and I committed to them we would work to deal with those issues."

She highlighted the rise in free childcare since the SNP came to power in 2007, saying: "No matter how hard Kezia Dugdale tries to manipulate the figures, she cannot get away from the fact that an increase from 412.5 hours of free childcare to 600 hours is a significant step forward."

Ms Sturgeon added: "This Government has delivered on childcare and we will continue to do so."

Ms Sturgeon highlighted the rise in free childcare from the "rather derisory" amount available to parents when Labour was in power at Holyrood, although she accepted there are still issues.

"This is a success story but we still have work to do," she told MSPs at First Minister's Questions.

Ms Sturgeon said she had met members of the Fair Funding For Our Kids campaign group last month "to discuss the experiences of some parents who are having difficulty in accessing the childcare their children are entitled to in a way that suits their working patterns".

She added: "There are some parents - and I stress some parents - who are having difficulty accessing their childcare in a way that suits their working patterns.

"For goodness sake, this is a massive success story, we've gone from an entitlement of children to 412.5 hours a year free childcare to 600 hours, and we have extended the eligibility for two-year-olds as well."

Ms Dugdale said while the First Minister had met the campaigners six weeks ago, they "haven't heard from her since".

Fair Funding For Our Kids have claimed the Government "give us supportive words but little action", the Labour MSP added.

"They told her that thousands of kids in Scotland are missing out on childcare and that parents are having to give up their jobs as a result."

Ms Dugdale challenged the SNP leader on the issue after the Family and Childcare Trust published a new report on childcare.

The Labour MSP said it showed just 15% of councils in Scotland say sufficient childcare is being provided for families in comparison to 43% of authorities in England.

She added: "Today's report confirms that fewer than one in six councils in Scotland are providing enough childcare for working parents, that's down from one in four last year.

"On the SNP's watch things are getting worse for families trying to juggle family life.

"One year ago today this Parliament gave parents of three and four-year-olds the right to 600 hours of nursery care. We supported that, we voted for it.

"But today's report makes it clear that parents across Scotland aren't able to access that right."

Ms Sturgeon told her: "We don't yet have sufficient provision of funded childcare to meet the needs of all full-time working parents.

"That's precisely why this Government is committed to a further substantial extension of the provision of childcare.

"We have said if we are elected over the next parliament we will increase provision to 30 hours a week for all three and four-year-olds and all eligible two-year-olds."

That would see children get 1,149 hours of free care over the course of a year, the First Minister said, challenging Labour to back this.

Ms Sturgeon claimed not even the "innumerate Labour Party can describe an increase in funded childcare from 412.5 hours a year, which is what they provided, to 600 hours a year, which what we are providing, as a deterioration".

While there has been a "significant improvement", the First Minister added: "I don't think that goes far enough, which is why I am committed to to moving to a situation where three and four-year-olds and eligible two-year-olds don't get 600 hours a year, they get 1,140 hours - 30 hours a week.

"That's my ambition, when will Labour get round to backing it?"