Gillian Shephard, Education and Employment Secretary, insisted parents would be provided with information and that the television adverts - costing Pounds 650,000 - would be " a politics-free zone".
At the launch of the report on the effectiveness of the pilot schemes in Norfolk, Wandsworth, Westminster and Kensington and Chelsea, Mrs Shephard said parents needed to be alerted to the scheme and the publicity was a tiny proportion of the overall cost of Pounds 750m.
"This is a completely new scheme. It would be considered deficient of us if we had not taken steps to make sure parents know about it," she said.
The plan to provide 650,000 parents of four-year-olds with a nursery voucher worth Pounds 1,100 will involve Pounds 165m of public spending on pre-school education. Inspecting private nurseries and voluntary playgroups is expected to cost a further Pounds 15m.
The Government, Mrs Shephard said, considered the pilots to have been "an extraordinary success", but there were no plans to introduce vouchers into any other area of the school system.
The survey carried out by the Department for Education and Employment found that in the state sector the scheme had resulted in a small reduction in the the number of three-year-olds receiving nursery education and an increase in the number of four-years-olds. In two-thirds of cases, numbers had not changed significantly.
Mrs Shephard acknowledged that there has been criticism from playgroups that they are being squeezed by the actions of some local authorities. "We have written to local authorities asking them to bear in mind that they should not crush out parents' desire and ability to choose the most appropriate setting that best suits their child, " she said. Parents will receive a guide that will help them assess the merits of the places available for their child.
The DfEE's research shows that 91 per cent of parents in the four pilot areas redeemed their vouchers. Of those, 97 per cent of the four-year-olds attended five half-days and 84 per cent three half-days.
But Dr Gillian Pugh, director of the Early Childhood Unit at the National Children's Bureau, said there is evidence to suggest that the scheme is not increasing choice for parents. She said the expansion in nursery provision in the pilot areas has been very small and a number of places had closed.