"Whether (it's) a or the customs union you still don't have the ability to do your own trade deals and she has said that one of the principles that we approach these talks with is that we want to be able to do trade deals around the world," the spokesman told reporters.

May's proposed Brexit deal was rejected by a large margin in a vote in parliament on Tuesday, and opposition Labour Party leader Jeremy Corbyn has called for an agreement which would see Britain being in a customs union with the EU.

(Reporting by Elizabeth Piper, Writing by Kylie MacLellan. Editing by Andrew MacAskill)