WTO warns on Brexit customs bill for UK exporters

London: British exporters risk an extra £5.6 billion ($8.2 billion, 7.2 billion euros) of annual customs duties if the country votes to leave the EU, the World Trade Organization (WTO) chief will warn on Tuesday.

Britain would have to negotiate new trade deals with the EU and with each of the 58 countries that have free-trade deals with the bloc, Director General Roberto Azevedo was to say at a conference in London, according to a copy of the speech obtained by AFP.

"This would probably entail negotiations," read the speech to the World Trade Symposium.

"In the meantime, while trade would continue, it could be on worse terms."

Most likely, it would cost more for the UK to trade with the same markets -- therefore damaging the competitiveness of UK companies.

"The implication is that UK exporters would risk having to pay up to £5.6 billion each year in duty on their exports," he was to tell the conference, according to the copy of the speech.

In addition, "there could be an impact on services trade", Azevedo will tell policymakers at the meeting, co-organised by the Financial Times.

Britain would also need to renegotiate the terms of its WTO membership and would not necessarily retain privileges afforded to other European countries whose membership is under the auspices of the EU.

"The UK, as an individual country, would of course remain a WTO member, but it would not have defined terms in the WTO for its trade in goods and services," the WTO chief was to say.

"It only has these commitments as an EU member. Key aspects of the EU´s terms of trade could not simply be cut and pasted for the UK."

A vote to leave on June 23 would present an "unprecedented" challenge for the WTO, making it impossible to set a timeframe for a deal to be struck, warned the speech.

"Negotiations merely to adjust members´ existing terms have often taken several years to complete - in certain cases up to 10 years, or more."

Britain´s need to agree deals quickly would put it in a weak negotiating position, he will say.  "It could take quite some time before the UK got back to a similar position that it has today."