"As soon as you put a hard border back in again... you undermine the basis of the Good Friday Agreement."

Jonathan Powell, chief government negotiator in Northern Ireland 1997-2007, explains why the Irish backstop matters

WATCH: https://t.co/tpEVcAhIcN#newsnight | @maitlis pic.twitter.com/oCBZaa4HJf

— BBC Newsnight (@BBCNewsnight) August 1, 2019