Parliamentary debate is important in making laws in democracies. Different political parties control who gets to speak in parliament. Parties decide which members can talk and which cannot. They do this to control the message their supporters give in parliament. The book talks about how parties make rules in parliament, how party leaders work with rebel members, and how MPs represent voters. The book looks at political institutions, party politics, elections, and how laws are made. The authors came up with a new theory about parliamentary debate and tested it using data from the UK, Germany, New Zealand, and the European Parliament.