Johannesburg - Trade union Solidarity lodged a formal complaint on Tuesday against Lonmin [JSE:LON] for recognising Amcu as the majority union, it said.
Solidarity general secretary Gideon du Plessis said this happened at a meeting of the mining sector national consultative forum.
The union contended that Lonmin had breached the framework agreement for a sustainable mining industry.
"By revoking its recognition of Solidarity and two other trade unions in favour of the Association of Mineworkers and Construction Union [Amcu], Lonmin is in breach of clause 5.3 of the framework agreement," Du Plessis said.
He said in terms of this clause, the "undemocratic" majority principle had to be phased out.
The government, organised labour and business signed the framework agreement last month.
Its objective is for all parties concerned to work together for stability and sustainability of the mining sector.
Du Plessis said Solidarity had also lodged a complaint with the Chamber of Mines, requesting action against Lonmin, and was waiting for feedback from the chamber and the office of Deputy President Kgalema Motlanthe.
Motlanthe's spokesperson Thabo Masebe said all parties agreed that the issue of trade union recognition needed to be resolved between the unions and employers within the framework of the Labour Relations Act.
"No final decision has been made at the forum, so that is a matter that remains on the table for discussion by all the parties," he said.
"It is a commitment by all parties so that the labour relations framework can be adhered to and allows for all inclusive participation within the mining sector from all parties."
Comment could not be obtained from the Chamber of Mines and Lonmin.