The renewed tension in Northern Ireland could have far-reaching implications for the future of the United Kingdom - and post-Brexit relations with the EU.

We spoke to Democratic Congressman Brendan Boyle, who sits on the House Committee on Ways and Means, which is responsible for international trade agreements.

Richard Haass, president at Council on Foreign Relations, discusses the state of Brexit amid a change of leadership in the U.K.

Channel 4 News has learned that some respected figures from the liberal wing of unionism are now ready to talk with the government in Dublin about Irish unity - and even a border poll.