It is difficult to see how there will not be any new checks between Britain and Northern Ireland if London pursues a trade agreement which is not aligned with the European Union, Arlene Foster, leader of Northern Ireland's DUP, said on Sunday.

Asked whether she believed Prime Minister Boris Johnson's assertions that there will be no new checks, Foster told Sky News: "It's difficult to see how that is the case given that we've heard from other members of the cabinet that they intend to diverge from single market regulations, whilst Northern Ireland remains within the single market. It's difficult to see how that's going to work."