Minority unions and non-union members can legally strike under notices served from majority unions, the Constitutional Court in Johannesburg ruled on Friday.
A majority judgment found that the Labour Relations Act only required 48 hours notice of a strike from majority unions.
Had the court found otherwise, the right to strike of non-unionised staff, and those belonging to minority unions, would have been restricted.
The court felt this interpretation was in keeping with the spirit, purport and objects of the Bill of Rights.
In November 2003, the SA Transport and Allied Workers Union (Satawu), the majority union of Equity Aviation Services (EAS), served the required notice and embarked on a strike.
Other employees who did not belong to the union participated, without giving notice themselves of their intention to strike.
In the company's view, the participation of those who did not give notice was unprotected, and the workers were requested to return to work. They failed to do so.
Equity later dismissed them for unauthorised absenteeism during the strike.
Previously, the Labour Court held in favour of the workers, and found that the dismissals were unfair because the employees were not required to be members of the union, or to give notice to strike.
The matter was taken to the Labour Appeal Court, but it agreed that non-union members need not give notice for their strike action to be lawful.
EAS appealed to the Supreme Court of Appeal, which reversed the decision. It ruled that separate notice had to be given for non-union members' strike to be protected.
Sapa