Firms need to prepare for single market, customs union exit, says UK PM's spokesman

Britain will be leaving the European Union's single market and customs union at the end of the year regardless of the outcome of talks and business should prepare for that, Prime Minister Boris Johnson's spokesman said on Wednesday.

"We will continue to approach negotiations constructively and work hard to reach an agreement, but whatever the outcome of negotiations, we will be leaving the single market and customs union at the end of the year," he told reporters.

"Businesses therefore need to prepare for life after 31 December, and many have done so already."