Esterman v NALGO [1974] ICR 625 is a UK labour law case, concerning trade union regulation.
NALGO balloted members for a strike, to increase the London weighting.
Miss Esterman refused to comply with the instruction and was disciplined according to NALGO’s rules.
The union had to have clear authority in the rules, and the member must have no reason to question whether the instruction was lawful.
There were doubts whether the union executive could ‘take the serious step of interfering’ with the member’s right to do work outside normal employment.