2009 Perak constitutional crisis

The 2009 Perak constitutional crisis was a political dispute in Malaysia over the legitimacy of the Perak state government formed in February 2009. It began when three Pakatan Rakyat state legislators defected, causing a collapse of the state government. The Sultan of Perak then refused First Minister (Menteri Besar) Mohammad Nizar Jamaluddin's request to dissolve the state assembly and call elections. Instead, the Barisan Nasional (BN), with support from the three defecting assemblymen, formed the new state government.

The BN state government's legitimacy and the Sultan's decision not to dissolve the state assembly was disputed vehemently by Pakatan Rakyat politicians. A series of court cases ensued between Nizar and the new Menteri Besar (First Minister), Zambry Abdul Kadir. Ultimately, in February 2010, the Federal Court confirmed that Zambry government was lawful.