Political parties form a pre-electoral coalition by publicly stating that they intend to form a government with each other if they receive enough votes in the up-coming elections. In many cases, however, political parties contest the elections completely independently, and voters therefore do not have any opportunity to accept or reject the post-election discussions leading to a new governing coalition.
By coordinating their campaigning strategies and sometimes even by harmonizing their political programmes, parties try to improve their chances to win as many seats as possible in the legislature. Sometimes, a political party may even give their supporters tactical recommendations to vote for the potential coalition partner, in order to ensure that all the political parties that are part of the pre-electoral coalition will gain enough votes to be represented in parliament. This is especially done in electoral systems where voters can cast two votes on one ballot and have the possibility to split their votes and may therefore support two different parties with the one ballot cast. If, for instance, supporters of a major party cast one of their votes in favour of the potential coalition partner, this may help both parties to gain representation in parliament.
Pre-election alliances are a common phenomenon in liberal democracies. Only in Western Europe, more than 200 pre-election coalitions were formed between 1946 and 2012. The forms of pre-electoral coalitions vary from party to party and from country to country, ranging from a loose promise to govern together to shared manifestos and voting recommendations.
One can classify pre-electoral agreements between political parties by the clarity of the commitment to govern together.
According to Carroll and Cox, the weakest form would be the pure announcement to work together, the second would be that parties announce a joint platform, the third that the partners would run joint district lists or a joint national list, and the strongest form would be that the coalitions negotiate mutual withdrawals, i.e. a candidate of one party in one district and a candidate of the other party in another district so that the two partners are not competing against each other in any district. In addition to these forms, the authors stress that looser forms of electoral cooperation between parties, i.e., as running just a few joint candidates or encouraging voters to vote for an ally, may occur (ibid).
Effect on representative nature of government
If a party receives the majority of vote shares and forms the government by itself, the voters may demand the government be accountable to them. Voters then have a direct influence over government policy. If, on the other hand, parties have to seek a coalition partner in order to gain a majority of seats, voter preferences are not necessarily reflected in the final coalition government.
Pre-election coalitions are said to be helpful in these cases, as they enable the voters to identify possible government alternatives even before the votes are cast. The voters may directly support one of the proposed coalitions and therefore furnish the new government with more legitimacy.
Conditions of forming pre-electoral alliances
Although the conditions of forming pre-electoral coalitions have not been explored systematically, one can find two major hypotheses about the factors influencing coalition formation.
The so-called disproportionality hypothesis states that pre-election alliances are more likely to arise in disproportional electoral systems if there are many or at least more than two parties. The basic assumption would be that the electoral system may have a considerable effect on coalition forming and alliances in the pre-election period.
Majority/plurality electoral systems usually advantage larger parties. If there are more than two competing parties in the party system, the major parties would tend to seek pre-election alliances in order to enlarge their chances of achieving a majority in the legislature and thus being part of the government. In these kinds of electoral systems, parties may for instance share their votes or even systematically transfer votes within their electoral alliances.
Another approach to explain the formation of pre-election arrangements would be the so-called signalling-device theory .The formation of party coalitions before elections is interpreted as a signal or a clear demonstration to the electorate that the party would be able to govern the country in a stable coalition. This can be especially valid in cases where opposition parties manage to form electoral coalitions against the ruling one-party government. If a major party has ruled for a very long time, the opposition parties may want to move closer together (i.e. ideologically), and to form alliances in order to try to replace the government.
