Defence Secretary Sir Michael Fallon is responding to an urgent question about Trident test firing; while peers turn to consideration of the Higher Education and Research Bill.
MLAs debate Economy Minister Simon Hamilton's proposals to limit the damage to the public purse caused by the failure of the RHI energy scheme.
The Scottish government outlines a new target of reducing greenhouse gas emissions by 66% by 2032
MEPs call for changes to EU social and employment law, and pass motions on human rights cases.
Committee members discuss the Welsh Language Standards. AMs quiz the Counsel General. There's a statement on the trade union bill. Debates are held on Tata Steel, the National Grid, bin collections and small businesses.
The Supreme Court ruling on the triggering of Article 50 is due on Tuesday and it means that we'll get some certainty about Parliament's future role.