In a representative democracy, opposition parties offer citizens the opportunity to vote for an alternative. If this choice is to be meaningful, opposition parties must behave distinctively from governing parties in parliament. However, previous studies found high levels of consensus in the law-making process between governing and opposition parties in European parliamentary democracies. Our understanding of when and why opposition parties support or oppose the government is surprisingly sketchy. This paper examines the factors that drive the extent to which opposition parties distinguish themselves from the government.

Existing studies have mostly focused on parliamentary votes within a limited time frame in one or two countries. This paper will analyse both parliamentary votes and parliamentary speeches in long time spans (approximately 70 years) in four countries with very different political systems: the Netherlands, Denmark, the United Kingdom, and Canada.

Policy concerns are expected to motivate opposition parties to support the government, e.g. when their policy preferences are similar or when the government accommodates wishes from opposition parties with veto power. However, electoral incentives are expected to drive opposition parties to signal their distinctive position to voters by opposing the government; these arise when opposition parties feel monitored by voters, e.g. when voters are volatile or when the issue at hand is salient. Additionally, the prospect of wholesaly replacing the incumbent government after future elections is also expected to increase opposition parties’ distinctiveness from the government.