Staff at Wakefield Council could go on strike in a dispute over conditions.
Members of the UNISON trade union, which represents around 4,500 council workers have been balloted for industrial action, after the authority made changes to its sickness policy.
A total of 77 per cent voted in favour of a walkout, though legally further ballots will have to take place before any strike action happens.
UNISON said the changes, which include introducing "attendance targets" for staff on long-term sick and scrapping review meetings for long-term absentees, would make it easier to sack workers.
A council report said that both UNISON and Unite had been consulted about the new policy, but that neither had attended meetings to which they'd been invited.
A branch official, who did not want to be named, claimed the changes to the policy make it far easier to dismiss workers who are ill, and who have health problems or disabilities.
They also claimed that a lot of the safeguarding measures which protect workers who are absent for a long-time have been removed.
UNISON officials also say they were "unaware" of the meetings the council said trade unions had been invited to attend.
In its report, which will go before a meeting of senior councillors next week, the council said that the changes aim to make life better for its employees.
The council said the new policy, which was implemented in May, had already cut the average number of days lost to long-term absence and would make the authority a more "caring" and attractive employer.
The report added: "The changes provide greater clarity for both employees and managers in a way which aims to have a positive impact on the overall sickness absence levels across the council, by enabling managers to have a better understanding of the issues employees are having to deal with, and so lead to attendance targets being put in place which are appropriate to each employee’s circumstances.
"These policies will provide for time off to be granted, often at short notice, in order to deal with a situation within their home life. The support of managers in providing this time off will reinforce our commitment to ensuring that the health and wellbeing of employees is a priority."
Unite has been contacted for their response to the new policy.