Updated

In a move that could have major political ramifications for the ruling African National Congress, the country's biggest trade union has called for President Jacob Zuma to resign and says it will not support the ANC in next year's elections.

The National Union of Metalworkers of South Africa, a member of the umbrella union movement COSATU which is one of the partners in the ruling ANC tripartite alliance, said the Zuma administration has been marked by one scandal after another.

The decisions were taken a special congress of the National Union of Metalworkers of South Africa, held east of Johannesburg.