Would-be Chinese investors in Europe are encountering a growing mood of protectionism among politicians and officials there who have raised barriers against many major deals. This is generating pressure to tighten the rules on Chinese takeovers, particularly where issues of fair competition and national security are said to be involved, and is twinned with demands for greater European access to investment opportunities in China.

The trend has been particularly apparent in Germany, whose Vice-Chancellor and Federal Minister for Economic Affairs and Energy Sigmar Gabriel upped the rhetoric ahead of a visit to China this past week by claiming it was strategically buying up German companies while protecting its own companies against foreign takeovers.

"Nobody can expect Europe to accept such foul play by trade partners," he wrote in a signed article in Germany's Die Welt newspaper. It was an unusual tone for an official to adopt before an overseas economic mission whose agenda included opening Germany's biggest business conference outside its own borders.