Coalitions
The 2009 general election saw three main national pre-poll alliances. Given the volatile nature of coalition politics in India, many parties changed alliances before, during and after the elections. The two larger coalitions, UPA and NDA, had clearly indicated their prime ministerial candidates during campaigning for the election. The Third Front announced repeatedly through the campaigning period that their prime ministerial candidate would only be decided after the election results came out. In Indian parliamentary system, the announcement of Prime Ministerial candidates prior to elections is not required.
Read more about this topic: Indian General Election, 2009