There are 67 nursery nurses working in state schools in the county. The proposals from Devon County Council would bring in a new job title of early-years assistant from September 1 this year. Pay would be protected for three years, but would then fall to the new level.
The change is a result of the single status agreement, signed by local authorities in 1997, which requires staff to receive equivalent pay for equivalent work.
It has already led some other authorities, including North Yorkshire, to pay nursery nurses on the same level as teaching assistants, and more are expected to follow.
A council spokesman said: "Currently, the salary paid to a full-time nursery nurse - for example, one who works 32.5 hours per week and term- time only - is equivalent to staff employed elsewhere in Devon County Council who work 37 hours per week and all year round. This undermines the requirement for an employer to give equal pay and conditions to staff undertaking work of equal value and could lead to a successful legal challenge."
One nursery nurse, who wished to remain anonymous, told The TES she was frustrated to be placed in the same pay bracket as an unqualified teaching assistant.
"I have a basic Btec early-years qualifications and an early-years foundation degree," she said. "Under the proposals I will end up with an annual salary of Pounds 11,000 for 32.5 hours a week."
Unison is fighting the proposals on behalf of its members. Fiona Bentley, regional organiser, said: "They are upset and angry about this. The experience of the staff is not recognised by the employer, who then use this as a justification for paying them less.
"Why doesn't the county come out and say, `We don't need that level of skill?' Is it because parents may come out and say they do want it for their children?"
Changes to early-years funding from next year (see story above) mean that state schools could lose money as the Government aims to create a fairer way of funding places, whether they are in the maintained or private sector.
Nursery nurses have expressed concern that this could mean further cases where their posts are downgraded or lost.