British Prime Minister Theresa May sits in front of British Foreign Secretary Boris Johnson during a meeting to discuss the current situation in Libya during the 72nd United Nations General Assembly at U.N. headquarters in New York, U.S., September 20, 2017. REUTERS/Lucas Jackson

LONDON (Reuters) - British Foreign Secretary Boris Johnson, who has described proposals for a customs partnership with the European Union after Brexit as “crazy”, said on Monday he backed Prime Minister Theresa May’s stance on the issue.

May has said Britain would leave the EU’s customs union and the “customs partnership” which would see Britain essentially collect tariffs on behalf of the EU in order to keep trade with the bloc flowing freely, is said to be her preferred plan for its replacement.

Writing in a newspaper on Sunday, May said she could be trusted to deliver Brexit, but that it could not be done without compromises on all sides.

“I thought the prime minister’s piece in the Sunday Times really set it out very clearly,” he said. “I think the prime minister’s position that I’ve now twice applauded is completely right.”