Malaysia follows the conventions of the Westminster system. For example, the prime minister must have the support of a majority in the Dewan Rakyat (House of Representatives), and must in any case be able to ensure the existence of no absolute majority against the government. In relation to the budget, that requires that if the House fails to pass the government's budget, even by one ringgit, then the government must either resign so that a different government can be appointed or seek a parliamentary dissolution so that new general elections may be held to re-confirm or deny the government's mandate.
