The authority's cabinet has agreed a new seven-grade pay scale which will see some employees get pay rises while others will have their salaries cut.

If they do not accept the new terms, staff will be sacked then immediately rehired, the council said.

But about 1,000 workers are to be balloted over possible strike action.

Unions claim the new contracts include no guarantees that bonuses will still be paid on top of basic salaries.

Council chiefs say this is a "legal requirement" and all jobs are safe.

Councillor Alan Rudge, cabinet member for human resources, said: "This requirement must be followed even though the council is seeking to retain all of our valued staff."

The overhaul is aimed at reducing long-standing wage inequality among staff.

Leaders claim the changes will mean a more "flexible and fair" work place for all and that only 12% will see their incomes fall.