Europe’s antitrust chief has urged the EU to ramp up its defences against the economic threat posed by Chinese state-owned enterprises while defending the competition rules that would allow her to block a rail merger that Paris sees as essential to countering Beijing’s ambitions.

According to documents seen by the Financial Times, Margrethe Vestager warned fellow members of the European Commission on Tuesday that the bloc’s antitrust rules should not be ignored to allow the planned merger of France’s Alstom with Germany’s Siemens railway division, despite warnings from Paris and Berlin that the tie-up is needed to build a rival to Chinese trainmaker CRRC.

However, Ms Vestager is unconvinced that the Chinese will sell trains in Europe in the foreseeable future and is bound by antitrust rules to block the deal unless the companies offer to sell off significant high-speed rail and signalling assets.