HM Revenue and Customs (HMRC) workers will vote on strike action following the dismissal of union representatives.
The Public and Commercial Services (PCS) union said three elected reps at HMRC Benton Park View, Newcastle, were sacked earlier this year for "demanding fair pay, pensions and jobs".
More than 200 union members are being balloted after PCS said managers were refusing to reinstate the reps.
A spokesperson for HMRC said it did not comment on staff employment matters.
Fran Heathcote, PCS general secretary, said the union believed the role the three reps played in last year's successful strike action over pay was the "real reason why they were sacked".
"Local management has clearly decided to attack the branch, to try to make it harder for the union to organise action in the future," said Ms Heathcote.
"It's not too late for HMRC managers to avoid strike action and the subsequent disruption to services if they do the decent thing and reinstate our reps."
The ballot will open on Monday and run until 9 December.