What has Boris Johnson said before?

At the start of the election campaign, the prime minister was asked in person by Northern Ireland business leaders whether they would be subject to customs declarations.

“You will absolutely not,” he told them. “If anyone asks you to do that tell them to ring up the prime minister and I’ll direct them to put that form in the bin.”

Potential checks were also at the centre of a row in parliament before the election began.

Johnson insisted there would be “no checks” on goods during Prime Minister’s Questions in October, directly contradicting Steve Barclay, the Brexit secretary, who admitted that Northern Ireland businesses will be forced to fill out export declaration forms when sending goods to Britain under the terms of the new Brexit deal.