|This article needs additional citations for verification. (November 2008)|
In many countries, party-switching takes the form of politicians refusing to support their political parties in coalition governments. This happens particularly commonly in countries without firmly-established political parties, such as Vanuatu and French Polynesia where in 2004, a few members of various parties left the governing coalition, forcing it to collapse. Party switches often occur with the formation of new parties — witness the situation in the United Kingdom, where some Liberals moved to the Labour Party in the early twentieth century. In formerly communist countries in Europe, de-Sovietisation saw many Communist-Party representatives switch to other parties ranging on the political spectrum from socialist to conservative.
In some cases, the defectors from an opposition party may choose to support a ruling coalition. In Poland, for example, the exit of the populist Samoobrona party from the government prompted a number of its members to leave and form a new parliamentary group.
Australia has seen high-profile defections since 1995, including the 1997 move by Cheryl Kernot (then leader of the Australian Democrats) to the Labor Party, the declared independence of former Labor senator Mal Colston (1996) and the disintegration of the Democrats.
However switching from one major party to another has not been a common occurrence in recent times.
Italy saw relevant examples of party switches during its republican history. Most affected by the phenomenon was the Italian Socialist Party which was in an ambiguous position, between Soviet-funded and revolutionary Communist Party, and the social-democratic area, not clearly choosing any of these two possible alliances. Italian Democratic Socialist Party switched from PSI in 1947 to become the leader of reformist left, while the Italian Socialist Party of Proletarian Unity switched on the other side in 1964 to search a stronger alliance with the PCI. If these switches were allowed by the pure proportional system of that time, situation did not change when the electoral system was turned into parallel voting in 1993, because coalitions leaders began to accept quite all new parties, ever if very little ones, in their alliances.
Party switching in New Zealand gained currency during the end of the 1980s, and even more so in the late 1990s after mixed member proportional representation was implemented. In particular, the phrase "waka-jumping" entered the public consciousness in 1998 when then-Prime Minister Jenny Shipley expelled the New Zealand First party from the ruling coalition government, and several New Zealand First MPs resigned from the party and stayed loyal to the government. In response to these defections, the Electoral Integrity Act was later passed in 2001, which later expired in 2005.
In Nicaragua some major party switches occurred between 2002 and 2006 when the two major political parties, the Constitutional Liberal Party and the Sandinista National Liberation Front, formed a pact and members of both parties left to form new parties or make alliances with smaller ones.
In Ukraine, the imperative mandate provision of the Ukrainian Constitution banned party switching in Parliament from 2004 to 2010. The mandate stipulated that the constitution and laws of Ukraine obliged members of the Verkhovna Rada, Ukraine's Parliament, to remain members of the parliamentary faction or bloc in which they were elected.
This was evident during the 2007 Ukrainian political crisis where members of the opposition crossed party lines with plans to undermine Presidential authority and move towards the 300 constitutional majority.
Party switching is not unusual in Turkey, but Kubilay Uygun is known for his repeated switching during his single term in the Grand National Assembly of Turkey (1995 – 1999). He resigned from his party seven times and served four different parties, finishing as an independent.
In the United States' political landscape, dominated by its two-party system, switches generally occur between the Republican Party and the Democratic Party. One notable "switch" took place in 2001 when Senator Jim Jeffords defected from the Republican Party to become a political independent, which placed the Senate in Democratic control. Use of the term party switch often connotes a transfer of held power from one party to another.
In the Russian Federation, party switching is considered illegal in the State Duma and is highly frowned upon. After major party switches during the Boris Yeltsin Presidency, party switching was declared illegal in the State Duma, and can result in a forced resignation of the State Duma representative by the chairman of their ex-political party. However, there is an exception. If a member of the State Duma is considered an Independent politician, he or she may be permitted to join and switch to a party at anytime. They may not switch after that. After a forced resignation, the State Duma representative can run again in future elections, as their new party's whip. The chairman of the political party can choose to replace the party switcher with whomever they choose. Party merging, however, is not illegal and can be seen when a big amount of political parties, including Yabloko merged into United Russia, the current ruling party of Russia.
- Crossing the floor, which in some Westminster systems may express a specialised meaning similar to party-switching
- Floor crossing (South Africa)
- List of Canadian politicians who have crossed the floor
- List of British Members of Parliament who crossed the floor
- Waka-jumping - party-hopping in New-Zealand