Eric Wilkinson of Glasgow University had earlier stressed that the private and voluntary sectors were "on the move and good luck to them". He warned Labour politicians not to dismiss the independent sector as elitist just because parents pay. "It is very different from the private school sector," he added.
Dr Wilkinson has a contract from the Scottish Independent Nurseries Association to devise quality standards which will be mandatory in all its 150-member nurseries.
Chris McIlroy, HMI, said standards would be guaranteed under vouchers by the initial registration required under the Children Act. Ten per cent of centres had had applications rejected.
The four pilot areas in Scotland had seen availability of places for four-year-olds rise significantly. The number of council nursery schools and classes had increased from 21 to 64, while 84 centres from the private and voluntary sectors had registered under the scheme. All 84 would be inspected by HMI this year.
Dr Wilkinson cautioned against premature judgments about the voucher scheme in advance of the pilot year evaluation by Stirling University. But he said it had two "worrying features": a concentration on children in their pre-school year to the disadvantage of the youngest and the "wasteful" use of a private company to administer the scheme. The contract with Capita Managed Services was extended this week for three years.