It would also send representatives to organise unions at factories controlled by multinationals and take court action if there were problems, Mr Yang said.

Mr Yang's remarks mark an ominous turn in the on-going spat between the federation and several multinationals that have invested billions of US dollars in the mainland, employing thousands of workers.

Official media last week accused Kodak, Wal-Mart, Dell, McDonald's, KFC and Samsung of abusing their economic clout by refusing to comply with mainland laws allowing workers to set up unions.

Mainland laws call for foreign-invested enterprises to set up labour unions and prohibit interference in the establishment of unions.

Kodak was accused of 'boycotting labour unions for years' at its Xiamen operations.

The photographic giant last week dismissed the reports as inaccurate and said it fully supported the establishment of labour unions as long as they were voluntary associations of employees.

Kodak added it was working with the federation to resolve the differences.

Xinhua's report yesterday targeted Wal-Mart, citing a Wall Street Journal report saying that the United States company would dismiss any employee found organising a union.

Guo Jun, director of the federation's legal department, said some multinational companies had prevented unionists from visiting their factories.

'This is obstructing the forming of unions and therefore violates the labour union law,' Mr Guo was quoted as saying.

Xinhua said local authorities would seek punitive fines against the multinationals.