The European Union should agree to a customs union with Britain to limit the impact on trade after it leaves the European Union in 2019, according to Germany’s BDI industry body.

“From a political point of view, a trade agreement is clearly more realistic,” BDI Managing director Joachim Lang told the Frankfurter Allgemeine Zeitung.

“But the idea of a customs union should not just be discarded, because from an economic point of view a free trade agreement does not go far enough,” he added.

As reported by the Reuters news agency, the call from the BDI, which is Germany’s biggest industry lobby and has close ties to Chancellor Angela Merkel’s Christian Democrats (CDU), comes after Britain’s CBI business lobby group earlier this year also called for a comprehensive customs union.

British Prime Minister Theresa May has, however, has ruled out remaining a member of the European single market and the European Customs Union, saying that Britain wants the freedom to negotiate its own trade deals.

German industry is concerned about increased friction in trade with Britain after Brexit. Britain is the second-biggest export market for German car manufacturers.