Alan Johnson, Education Secretary, accepted proposals to form a national negotiating body that would create a pay and conditions structure for support staff.

This follows more than 18 months of heated debate between the Department for Education and Skills, unions, employers and representatives of self-governing schools.

The move has been warmly welcomed by unions, who said it would stop staff being paid on the “whim” of headteachers.

Anne Musgrove, a higher level teaching assistant with 15 years experience, who takes home pound;930 a month, said a national pay structure would give support staff a sense of being valued.

Mrs Musgrove, from Thackley primary in Bradford, said: “Our goodwill has been exploited for a long time.

“This will give us greater standing and ensure we are paid according to the work we actually do.”

Talks on the issue have dragged on since November 2005, when the Government first formed the working group to investigate support staff pay. They did not report back until this month.

Their report said that the new negotiating body would cost pound;250,000 a year to run.

Local Government Employers (LGE)initially opposed the plans, concerned over the potential cost.

They are seeking legal advice about how it would affect last year’s “single-status agreement”, which requires a school accounts manager to be paid the same as a town hall accounts manager.

Phil White, head of negotiations at LGE, said they were still “not entirely convinced by the necessity” of a national pay structure, but they would co-operate with the minister’s call to press ahead.

There were also concerns about how a single pay structure might affect the growing number of self-governing schools.

Foundation and trust schools are expected to come under the pay structure, giving them less flexibility, but academies are not.

Christina McAnea, national secretary for education at Unison, which represents 200,000 support staff, said it would take until around September next year to assemble the pay body and devise a structure of pay and conditions.

She said: “Many school workers’ pay does not reflect the job they do and is determined almost on the whim of the headteacher.

“We need a national framework that will apply in all schools. The alternative is the nightmare scenario of pay negotiations taking place separately in 23,000 schools.

“A national pay and grading structure therefore benefits the schools themselves, and the staff.”

Brian Strutton, head of support staff negotiations for the GMB union, said the move would help resolve issues around staff only being paid on a term-time basis.

The Church of England has also offered its commitment to the principle of equal pay rates for support staff in all types of school.