Canadian Constitutional Law/Charter of Rights and Freedoms
The first section of the Charter, somewhat surprisingly, is the main section placing limits on the rights and freedoms contained in the Charter. Section 1 states: “The Canadian Charter of Rights and Freedoms guarantees the rights and freedoms set out in it subject only to such reasonable limits prescribed by law as can be demonstrably justified in a free and democratic society.”
For Charter rights to be limited, the limits must meet three requirements:
They must be reasonable in a free and democratic society
They must be prescribed by law
They must be demonstrably justified
The second and third requirements are relatively clear. “Prescribed by law” means that the limits must be written either in legislation or regulation. A governmental limit on Charter rights cannot be arbitrarily decided by an official. Nor can it be contained in rules which do not amount to “law”, such as administrative manuals. “Demonstrably justified” means that the burden of proof is on the government to prove that the limits it has imposed are reasonable. In court, this means that once the plaintiff proves on a balance of probabilities that his or her rights have been violated, the government must prove on a balance of probabilities that it is reasonable.
On the other hand, the question of what constitutes a “reasonable limit” in a “free and democratic society” is perhaps the most important question of modern constitutional law. Most major Charter cases in Canada do not turn on the question of whether a right has been violated (the courts often find that it has been), but whether the law constituted a reasonable limit on that right.
The test for deciding whether the violation of a Charter right is a reasonable limit on a right or freedom was created by the Supreme Court in R. v. Oakes,  1 S.C.R. 103. Known simply as the Oakes test, it asks the following questions:
Is the purpose of the legislation to limit the charter right or freedom? If so, it is not a reasonable limit.
Is the limit proportional to the objective? It is if it meets all of the three following criteria:
The limit has a “pressing and substantial objective”
The limit infringes on the Charter right as little as possible to meet its objective (aka the “minimal impairment test”)
The benefit of the limit is greater than the harm caused by limiting the right or freedom
The Oakes test is still used by the Supreme Court, although it has nuanced the second part of the proportionality test. The Supreme Court found that a limit on a right should infringe at right “as little as possible” when the objective of the law is to set relations between the government and the individual (for instance, in criminal law, where it is the government against the individual). However, the government should have more flexibility when trying to strike a balance between different groups of people. This latter case would come up most often in areas of social welfare. Where the government cannot afford to give everyone equal benefits, it will almost always have to create a somewhat arbitrary dividing line, such that some people have their right to be treated equally violated. The Court must give some flexibility to the government in deciding whom to give benefits and whom to deny. In such a case, the Supreme Court reasoned in McKinney, the “minimal impairment test” is whether the government had a reasonable basis for believing that the right to equality has been violated as little as possible to achieve the government objective