The fundamental principle at the heart of our parliamentary democracy is that the government must command the confidence of the House of Commons. In the event of a hung Parliament, where no party secures an outright majority, the arithmetic presents politicians with a conundrum: who commands MPs' confidence, and should therefore govern?

The answer to this question is determined through a complex nexus of constitutional conventions, laws and precedents, party political calculations and gauging of the public mood. Guidance and rules exist to help resolve who should govern, including in the form of the Cabinet Manual and the Fixed-Term Parliaments Act.

This June 2017 briefing paper addresses how a government is formed and then sustained in office when the House of Commons is hung, focusing on the 2017 situation. It also looks at how a minority government might operate in Parliament, focusing on the impact it may have on parliamentary process and procedure.