Vouchers did not meet the cost of new building, the extra costs of providing places in rural areas and for children with special needs, and failed to meet parents' demands for extended nursery hours, councillors heard on Tuesday.
John Travers, the council's director of education, said: "Many of the criticisms put by the council initially have been proved to be well-founded. " By participating, the council had been able to provide an informed critique, Mr Travers said.
Nursery heads complained of excessive time spent signing vouchers. The scheme involved the parent and headteacher signing five a term. In an 80-place nursery, that meant 800 signatures before the vouchers could be passed to the education department. The process was repeated three times.
North Ayrshire maintains it was justified in testing the system. Before it accepted the pilot in spring last year, fewer than 31 per cent of children had a nursery place in their pre-school year. After it joined, the number of places rose from 767 to 1,337.
The council states: "It should be noted that Pounds 770,000 will have been spent on nursery education in North Ayrshire which would not otherwise have been available to the council, thus providing 700 additional nursery places. "
Irene Oldfather, education vice-convener, said: "These statistics speak for themselves." The project had widespread support and the council was lucky it had spare capacity without incurring heavy capital expenditure. She warned: "Some local authorities won't be in the fortunate position we were in and indeed the minister has indicated that a voucher does not necessarily mean a nursery place."
A survey of parents showed strong support for nursery expansion, the priority given to pre-school children and the free service for people who previously had to pay. But in Arran, which has an established tradition of playgroups, there were reservations about a more formal approach. There were also fears about damaging voluntary and private sector provision.
But parents liked having a nursery class attached to their local primary and because of the monetary value of the Pounds 1,100 voucher became more aware of services.
What parents said
* "I like the money I have saved which I now use to pay for private care for my son who does not, as yet, qualify for the voucher scheme."
* "One advantage about getting the voucher is that I no longer need to do duties in the playgroup and being a working mother it was not easy finding someone to take my turn."
* "I did not like that you have to apply for vouchers. They get sent to you and then we have to send or take them and hand them in to the nursery. It should all be done direct."
* "I think it would be a more practical solution for the actual nursery vouchers to be sent directly to school rather than to the child's home. "
* "I feel that the funds I am paying a private nursery may in some way be subsidising the other activities in that nursery (babies 6 weeks to 4 years attend)."