U.K. Prime Minister Theresa May is planning to return to Brussels to renegotiate the Northern Ireland customs backstop, former Foreign Secretary Boris Johnson writes in the Daily Telegraph, citing “very senior” government sources.

Johnson called May’s plan “unadulterated good Brexit news,” adding that an exit mechanism will “defuse the booby-trap” and allow the U.K. to find a way out and negotiate a Canada-style free-trade deal.

“And if the PM secures that change –- a proper U.K.-sized perforation in the fabric of the backstop itself—I have no doubt that she will have the whole country full-throatedly behind her,” Johnson said.