One primary headteacher said: "Information seems to be regarded as 'top secret'. It has all become slightly furtive and competitive."
Many primaries feel under pressure to admit under-fives who would normally have been in playgroups and nurseries. As well as reception (Year R) children, who become five between September and August, schools are now considering Year 0 pupils - in Norfolk, those who have their fourth birthday between September and the following August.
A head of another primary, which does not have a nursery, said: "As a head with a nursery-teaching background I felt we should not offer places to Year 0 pupils - I'm not totally happy about Year R (reception). The governors felt we had to because otherwise we would lose families, which in a school our size would be disastrous."
A total of 120 (38 per cent) Norfolk primary heads out of 319 returned the complex questionnaire on nursery vouchers which covered admission policies, staff:child ratios, training, and liaison between schools, nurseries and playgroups.
All but 15 heads gave nursery vouchers the thumbs-down, compared to six who welcomed them; the remaining nine did not answer the question. The survey was undertaken last summer by the Norfolk Primary Headteachers Associations with the support of Norfolk County Council.
Cathy Whalen, headteacher of Mousehold First School and Nursery in Norwich and one of the co-ordinators of the survey, said the most serious finding was the extent of "anxiety, mistrust and competition" between schools, nurseries and playgroups. Nursery vouchers were diverting concentration away from quality to finance.
Or as one headteacher reported: "The nursery vouchers have made education providers competitive and undermined co-operation. I am appalled that this vulnerable group of pre-school children should be so badly treated, their parents confused and school viability undermined."
Another head said: "It has been very stressful and has adversely affected my relationship with some parents and playgroup leaders who don't want their children to start school until they are five-plus."
The survey found that schools were changing admission polices because of the incentive to increase funding and the benefit of earlier admission to summer-born pupils.
Other heads were concerned about competition from neighbouring schools: "If I don't take them, others will - end of village school."