Parliament has three main functions which may be described as legislative, financial and critical. Only Parliament can pass laws, impose taxes and authorize public expenditure. The critical function is largely exercised by the Members of the opposition parties, who have a duty to the country no less important than that of the Government. A highly significant feature of the parliamentary system is that the Opposition has an officially recognized status. The leader of the Opposition, who is the leader of the party in opposition having the largest number of members, is paid by the state, and like all arties, Government and Opposition alike, are provided with money for research.
Since Parliament spends most of its time dealing with government business its critical function is of great importance. The opposition parties are always anxious to keep the government "on its toes" and by making the most of their parliamentary opportunities they are able to exert their influence both on government and public opinion. All parties are concerned with the impact they are making in the country and none, whether in or out of power, can afford to ignore the views of its opponents. The unceasing confrontation of political parties and the cut and thrust of debate between them are essential to the parliamentary system.
All members of Parliament are free to vote as they choose on the various matters which come before the House, but they rarely vote against their own parties on major issues. The effective operation of Parliament depends today upon the party system which assumes that in most circumstances a party can count on the solidarity of its supporters. As already noted, the parties in opposition are officially recognized. The leader of the Opposition is entitled to the same salary as a Cabinet minister in addition to his indemnity and allowances as a Member of the House of Commons. In the official order or precedence he ranks immediately after the members of the Cabinet.
The job of the opposition parties is to scrutinize everything that the government does; to criticize its measures and policies and propose alternatives of their own; and to draw attention to any inefficiency or maladministration in the conduct of national affairs. But an opposition does more than merely oppose. Its aim is to be constructive and there are occasions when an opposition party decides that it is in the national interest to co-operate with the Government.
The Principal opposition party normally regards itself as a government-in-waiting and its leader as a potential Prime Minister. The system assumes that at any time an alternative government is standing by and ready to assume the responsibilities of office. As a part of this preparation leading members of the opposition, sometimes designated 'shadow ministers', do duty as critics of the various departments of government., acting as counterparts to the ministers of the Cabinet.
The rules and practice of the House of Commons protect the rights of the opposition parties in various ways. There are days when they have the right to select the subject for debate; they are usually given precedence by the speaker during the daily question period; and opportunities for expressing lack of confidence in the government occur regularly.