Industrial action over the benchmarking report is to be considered by a union representing 11,000 civil servants, which claims the report favoured those on higher incomes.
The Civil and Public Services Union (CPSU) is also to take a case to the Equality Tribunal, alleging that the report discriminates against women workers.
Delegates to a conference of the union on Saturday angrily condemned the report for its "lack of transparency" and failure to take on board their concerns.
The union represents clerical and staff officers at the bottom of the civil service pay scale, and 80 per cent of its members are women. Several speakers said it was no coincidence that the other group that was most unhappy with the benchmarking outcome was nurses.
The nursing profession was also dominated by low-paid, women workers, said Mr Terry Kelleher, a member of the CPSU executive. "Benchmarking was supposed to eliminate the gap between the haves and have-nots in the civil service, but instead it has widened it," he said.
CPSU members are due to receive raises of between 8.5 per cent and 10 per cent from the benchmarking report, compared to 13.8 per cent for assistant principal officers.
Mr Blair Horan, the union's general secretary, said the benchmarking body hadn't paid "a blind bit of heed" to the CPSU's arguments about fairness in the pay structures.
There had been no transparency in the way the body, which issued its report in July, had reached its conclusions, he said. It had provided no evidence to support its evaluation of different grades, or any details about the private sector pay rates it had used for comparisons. Members had been "angry and disappointed" at the outcome.
The 250 delegates present voted overwhelmingly to ballot members on the report, with a recommendation from the conference that they reject it.
Ms Rosaleen Glackin, the union's deputy general secretary, said a further ballot would be required before industrial action could be undertaken,
However, a sub-committee set up to examine the possibility of such action had done "a considerable amount of work", she said.
The motion passed at the conference also instructed the general secretary to "refer the matter for investigation under the Employment Equality Act of 1998".
This would enable the union to challenge the benchmarking outcome on the basis of "gender discrimination", said Ms Glackin.
The union is to consider seeking the assistance of the Equality Authority, or may take a case directly to the Office of the Director of Equality Investigations, also known as the Equality Tribunal.
Mr Blair told the conference that 46 per cent of the CPSU's civil service members earned less than €20,000 a year.
One delegate, Ms Nicola Coleman, of the Central Statistics Office Dublin branch, said she was a clerical officer on the lowest point of the pay scale. After tax, the 8.5 per cent awarded to her came to €5.31 per week.
