Staff at Lawnswood Crematorium are holding a one-day strike tomorrow as part of a long-running dispute with the city council.
The four members of the Unison trade union say claims of harassment, bullying and unsafe working conditions have been ignored.
They also say that two members of the union are now being threatened with “serious disciplinary action”.
Unison regional organiser Dean Harper said he was “deeply concerned” by the situation.
The striking staff are due to stage a demonstration outside Leeds Civic Hall from 8am tomorrow.
Leeds City Council said the walkout would not affect planned cremations at Lawnswood.