The US, European Union and Mexico have asked for a World Trade Organisation dispute panel to investigate Chinese restrictions on exports of specialised raw materials used in industry, the latest indication that the global slowdown is leading to greater international action against China’s trade policies.

The request to the WTO claims that China’s restraints on exports of bauxite, magnesium and other raw materials, which are used to make steel, aluminium and some chemicals, is driving up the price of those end products.