London

The UK must not enter into a new customs union with the European Union after it leaves the bloc, Trade Secretary Liam Fox said, setting a new red line for Theresa May’s negotiations with Brussels and her own party on Brexit.

Fox, a long-standing Euro-sceptic, told Bloomberg that the UK must not sign up to the EU’s common external tariff, which binds all EU member countries to the same rates. His comments follow a report in the Financial Times that said May’s officials are considering keeping Britain in a new customs union, and the external tariff arrangement.

“It is very difficult to see how being in a customs union is compatible with having an independent trade policy because we would therefore be dependent on what the EU negotiated in terms of its trading policies and we’d be following behind that,” Fox said.

Fox was expanding on earlier comments, in which had said the UK couldn’t be part of any agreement with the EU that prevents him striking new bilateral deals with other countries.

Under current terms of customs union membership, EU member countries are banned from negotiating free trade agreements with other countries. The EU strikes deals on behalf of all 28 member nations instead.

Courting China

May is seeking to build global trade relationships as she prepares for the U.K.’s impending March 2019 departure from the European Union. She has put an early focus on courting China — the world’s largest trading nation — as a partner in a future free-trade agreement.

China signed 9 billion pounds ($12.8 billion) of business agreements in areas covering finance, agriculture, technology and China’s Belt and Road Initiative, which seeks to forge new trade and infrastructure links across Eurasia.

Fox told Bloomberg on Friday that he hoped to have a link between the London and Shanghai stock exchanges “up and running as soon as we can, as soon as it is a practical option.”

He also defended his boss: “Theresa May’s middle name is resilience,” Fox said. “And that’s exactly what she’s showing and I do wish more people could have seen the commitment she was showing to Britain’s national interest on this trip to China.”