Stormont crisis - what will DUP do? @AlexKane221b and @JonTonge discuss. #BBCNolan

A bitter war of words between unionism's two biggest parties is escalating. The DUP and UUP are at each others throats after Mike Nesbitt pulled the Ulster Unionists out of the executive.

The DUP are due to meet the prime minister today to discuss the current crisis at Stormont.

Northern Ireland Secretary Theresa Villiers is also scheduled to meet two Irish government ministers in Dublin.

And the UUP will formally withdraw its only minister, Danny Kennedy, from the executive later this afternoon because they say they cannot trust Sinn Féin.

To discuss the latest developments Nolan talks to commentator Alex Kane and Jon Tonge, who is professor of politics at the University of Liverpool.