Under the Westminster system of government, the normative basis of political accountability of the government is provided by constitutional conventions being the norms of an informal and extralegal nature. Consequently, there are no formalized procedures to hold the government politically accountable to the parliament, which would allow the latter to pass a vote of no confidence in the government. Currently, the Cabinet is accountable only to the lower chamber of parliament, which means that only the loss of confidence of the House of Commons in the United Kingdom and Canada, and the House of Representatives in Australia, imposes on the prime mister a constitutional obligation to submit his resignation or to bring about the dissolution of parliament. Parliament may express a vote of no confidence directly or indirectly, and, in the practice of governance, the possibility of withdrawal of confidence from an individual member of government has been eliminated. The defeat of a supply bill (one that concerns the spending of money) is an indirect form of expressing a vote of no confidence. Any voting in parliament may be transformed by the prime minister into a motion of no confidence, who is required to make a declaration to this effect. The specificity of the procedures for passing a vote of no confidence by parliament under the Westminster parliamentary system is evident in the lack of traditional instruments to rationalize political accountability of the government. In these circumstances, rationalization of political accountability manifests itself in limiting the possible use of indirect form of passing a vote of no confidence almost only to refusal to authorize the expenditure of funds on government activities, consideration only those motions of no confidence which are submitted by the Opposition leader, as well as exclusion of the possibility of unexpected fall of a government having majority support in the parliament, inter alia, by the use of the mechanism of pairing. However, the lack of classic mechanisms rationalizing political accountability of the government does not result in strengthening of the position of parliament in relation to the government, as could be manifested by a frequent application of the motion of no confidence by the legislature. In practice, a stable two-party political system enabling the creation of majority one-party Cabinets, should be considered to the most important mechanism for rationalization of political accountability of the government.