Britain's Chancellor of the Exchequer, Philip Hammond, arrives back at 11 Downing Street, in London, Britain November 15, 2018. REUTERS/Henry Nicholls

LONDON (Reuters) - Leaving the European Union without a transition deal would cost Britain tens of billions of pounds, and failure to support Prime Minister Theresa May’s preferred plan could jeopardise Brexit altogether, Chancellor Philip Hammond said on Wednesday.

“A smooth exit from the European Union, doing this in an orderly fashion, is worth tens of billions of pounds to our economy,” Hammond told broadcaster ITV.

“If the deal is not approved by parliament, we will have a politically chaotic situation ... In that chaos that would ensue, there may be no Brexit,” he added.