Other countries, suggests Philippe Mellier, chief executive of Paris-based Alstom Transport, should consider blocking Chinese train exports. It is only the latest sign of worsening tension about increasing competitiveness of Asian train manufacturers.

Builders in China, Japan and South Korea tended in the past either to develop technology for purely domestic use or to work with technology imported from one of the three big international manufacturers - the German-based trainmaking operation of Canada's Bombardier, France's Alstom or Germany's Siemens.