Strike action against Wandsworth Council is being stepped up by Unison as the row over a proposed absence policy escalates.
Of a 50 per cent turnout, eight out of 10 members voted to stage a one-day strike tomorrow (Wednesday) followed by two days on 2 and 3 February.
Under the proposed clampdown staff will have to use up holiday or pay back lost hours if they take too much sick leave.
Negotiations were continuing as Personnel Today went to press.
TUC coordinator John Perry said, "Staff have been insulted and condemned unfairly as malingerers. The council is now trying to bully them by threatening to reduce annual leave if they don't accept this."
But Wandsworth Council spokesman Steve Maynar said the ballot figures show only 10 per cent of staff back the action.
"We are determined to bring down sickness levels and negotiations are continuing," he said.