Representation in the House of Representatives is based on population and ‘original states’ have equal numbers in the Senate. The two houses are equal in power except for certain restrictions in financial matters. For example, the Senate may not amend a supply Bill, although as the Australian constitutional crisis of 1975 demonstrates, it may defer or refuse to pass such a Bill altogether; Bills to impose taxation or appropriate revenue may not originate in the Senate; and the Senate may not amend a Bill so as to increase taxation.