Almost half of the Unison members in the survey work as local government employees in primary schools or council-run nurseries, while only 9 per cent work in private schools and nurseries.
Bruni de La Motte, Unison's education officer, says, 'We have been trying to get into the private sector but this is very difficult, especially with the big companies.
'When we have contacted colleges where nursery nurses are training we have had quite a good response. Young people are interested in joining the union if we contact them before they start work.
This campaign also confronts the age profile of union membership within the childcare sector: three-quarters of the Unison members are over 31 years old.