Anger, tangle and trouble: Is another Brexit showdown looming?

FILE PHOTO: A Union flag flies next to the flag of the European Union in Westminster, London, Britain June 24, 2016. REUTERS/Toby Melville/File Photo

LONDON/BRUSSELS (Reuters) - What happens if Britain triggers emergency unilateral provisions in the Brexit divorce deal known as Article 16?

WHAT IS ARTICLE 16?