AS Scottish parents have just found out, educational policy can be similar to insurance when it comes to the small print.

Terms and conditions apply.

Earlier this year, the Scottish Government passed legislation giving families with three and four-year-old children a "mandatory" 600 hours of free childcare every year.

Never knowingly undersold on policy announcements, First Minister Alex Salmond hailed it as the best package of free nursery education on offer anywhere in the UK.

It was a message heard loud and clear by working families across Scotland with eligible children. As far as they were concerned, the Scottish Government had made an unequivocal commitment to provide them with the specified free hours without strings attached.

So why is it, as The Herald reported yesterday, that hundreds of children attending private nurseries in a number of council areas, including Glasgow and East Lothian, have been told they cannot access the money? Back to those terms and conditions.

In fact, the "contract", if it can be called that, is not between the Scottish Government and parents. It lies instead between the Scottish Government and councils, which have a statutory duty to deliver the policy.

The Children and Young People (Scotland) Act 2014 states: "An education authority must, in pursuance of its duty ... secure that the mandatory amount of early learning and childcare is made available for each eligible pre-school child belonging to its area." There are two crucial consequences from the way the legislation is worded.

One relates to funding, with councils expected to deliver the policy from the grant they receive for all public services in their area. So there is no sum of money per person that can be passed on to parents. The second consequence of the decision to deliver the policy through councils is that they naturally seek to use as much of the funding as possible in the nurseries they run themselves, with money passed on to private nurseries only when they have insufficient capacity to meet demand - so places may be available, but not necessarily in the nurseries parents have chosen.

Unfortunately for working families, council nurseries, despite being amongst the best in Scotland, are hard to get into, do not offer enough hours of care to cover the working day and are also closed in the school holidays. That means parents have no option other than to use private providers, even if spaces are available in council nurseries.

What makes the situation more frustrating in Glasgow and elsewhere is that funding to private nurseries is not allocated on the basis of where the children are, but is dependent on the council's judgment of the quality of the establishment and an estimate of demand in the area. That means parents who have chosen a nursery that has been allocated fewer places - or none - have no option other than to move their children around in order to access the funding.

It is little wonder there is an increasing clamour for the Scottish Government to have a rethink and ensure money follows the child, rather than the other way round.