Section 18 of the Constitution Act, 1867

Prior to Confederation, issues arose in the British North American provinces about the parliamentary privileges of the legislative assemblies. In some cases, the assemblies claimed the same privileges as the British Houses of Parliament, while in other cases, they claimed more limited rights, such as only claiming freedom of speech in the assembly.^[23][24]

During this period, the scope of the privileges of the assemblies sometimes arose in judicial proceedings, and sometimes required legal opinions from the British law officers of the Crown. The conclusion drawn was that colonial legislatures did not have the same privileges as the British Parliament, which were based on the historical origins and the lex parlamenti of the British Parliament. Instead, colonial legislative bodies had only those privileges which were necessary for the functioning of a legislature, such as freedom of speech in the assembly. The colonial legislative assemblies did not have the more extensive powers of the British Parliament, such as the power to commit an individual for contempt of Parliament.^[23][24]

An additional limitation was that the Crown, acting through the British government, did not have the power to confer broad privileges on a colonial legislature. Only the British Parliament could give those powers to a colonial legislature, by statute. That was the reason for section 18 of the Constitution Act, 1867, to give the Parliament of Canada the same privileges as that of the British Parliament.^[21][23][24]

Six years after Confederation, in 1873, a serious political scandal arose which tested the limits of the privileges of the Parliament of Canada. The Pacific Scandal was triggered by allegations that the Conservative Party, led by Prime Minister John A. Macdonald, had received large donations for the 1872 federal election, from a business group led by Sir Hugh Allan of Montreal. Allan was seeking the federal contract to build the Canadian Pacific Railway, a transcontinental railway to the Pacific coast. When the scandal broke, the opposition Liberals called for a parliamentary inquiry, with the power to compel testimony under oath.^[25] The Parliament of Canada passed a statute, the Oaths Act, to give the committee that power.^[26][27]

Questions were raised almost immediately about the constitutional validity of the act. The original version of section 18 limited the parliamentary privileges of the Canadian House of Commons and the Senate to the privileges possessed by the British House of Commons at the time the Constitution Act, 1867 was passed. However, in 1867, the British House of Commons did not have the power to compel testimony under oath; it only obtained that power by a British statute enacted in 1871.^[28][29] The issue was whether the 1873 Oaths Act improperly expanded the parliamentary powers beyond what had been allowed in 1867. Macdonald indicated in the debate on the bill that he shared the concerns whether Parliament had the necessary authority to enact it, but he was prepared to agree to its passage.^[26]

Macdonald, in his capacity as Attorney General of Canada, drew the issue to the attention of Governor General Dufferin. Macdonald indicated that he shared the serious concerns being raised about the constitutionality of the act, and asked the Governor General to consider referring the issue to the British government for a legal opinion.^[30] Dufferin also had the benefit of an opinion from Alpheus Todd, a leading Canadian expert on British parliamentary practice. Todd disagreed with Macdonald and concluded that the Oaths Act was constitutional.^[31] Dufferin referred the matter to the Colonial Secretary, the Earl of Kimberley, including the memos from Macdonald and Todd.^[32]

A month later, the response came from the British government: the law officers of the Crown had concluded that the Oaths Act was outside the authority of the Parliament of Canada.^[33][34] The British government therefore advised Queen Victoria to disallow the act, under s 56 of the Constitution Act, 1867.^[35][36] This was the only case of the British government disallowing a federal statute.^[37]

In late 1873, the Macdonald government resigned over the Pacific Scandal and the Liberals came to office under Alexander Mackenzie.^[20] The new government of Alexander Mackenzie responded to the issue of the limited scope of section 18 by asking the British government to amend section 18 to broaden the powers of the Canadian Parliament. The Mackenzie government did not first raise the issue in the Canadian Parliament. Without any debate, the British Parliament enacted the Parliament of Canada Act, 1875. The constitutional amendment had essentially been made by the Canadian cabinet.^[12][38]

When the passage of the amendment became known in Canada, Conservative opposition members of the Canadian House of Commons protested. They argued that any constitutional amendment first had to be approved by the Commons and the Senate, before the request was made to the British government. The Conservatives pointed out that just four years earlier, in 1871, the Liberals (then in opposition) had taken exactly that position with respect to the proposed enactment of the British North America Act, 1871 (now the Constitution Act, 1871). The Conservative government had agreed with the Liberals in 1871, and had introduced the proposed amendment in the Commons and Senate before forwarding it to the British government.^[22][38]

Speaking in the House of Commons, Prime Minister Mackenzie conceded that it would have been better to have first raised the proposed amendment in the Canadian Parliament before making the request to the British government. He agreed that course should be followed for future amendments.^[22][38]

Parliamentary privilege covers the individual privileges of members of the House of Commons and the Senate, and the collective privileges of the two houses. Both sets of privileges have their roots in the essential independence for members, needed to carry out their duties. The privileges have evolved over the centuries, with their roots in the English and British House of Commons.^{[23][41][42][43]}

The individual privileges of the members are as follows:^[44][45]

• freedom of speech;
• freedom from arrest in civil actions;
• exemption from jury duty;
• exemption from being subpoenaed to attend court as a witness when Parliament is in session; and
• freedom from obstruction, interference, intimidation and molestation.

Of these, freedom of speech is the most important.^[44]

The collective rights of each house are as follows:^[46][47]

• the regulation of its own internal affairs;
• the authority to maintain the attendance and service of its members;
• the power to discipline;
• the right to institute inquiries and to call witnesses and demand papers;
• the right to administer oaths to witnesses appearing before it; and
• the right to publish papers without recourse to the courts relating to the content.

Of these rights and privileges, the right of the house to regulate its own affairs, and the power to discipline, are the most important.^[46]

The Preamble to the Constitution Act, 1867 provides that Canada is to have a Constitution "similar in principle to that of the United Kingdom", which has been held to be an additional constitutional basis for parliamentary privilege.^[43][48]