Judicial review is a term that generally relates to how an appellate court understands the nature of the case before them, a concept most easily seen when the case involves civil rights. The term also refers to the very right of a State (governmental) Court to review a legislative law or executive action (see Marbury v. Madison for the US precedent), as opposed to the Court merely being able to adjudicate matters between parties.
In US jurisprudence, there are three levels of judicial review: Rational review (the "lowest" level of scrutiny and the most common for appellate courts), intermediate scrutiny and Strict scrutiny (a level of review required for cases involving discriminatory laws regarding suspect classes or fundamental constitutional rights).
In the UK, judicial review usually takes the form of a review of secondary legislation or regulations passed by a Minister, local council or tribunal. The Courts can rule that the decision taken was illegal (i.e., outside the powers afforded to the decision-maker by the Enabling Act), irrational (i.e., "so outrageous in its defiance of logic or of accepted moral standards that no sensible person who had applied his mind to the question could have arrived at it") or procedurally improper (i.e. the wrong process was employed.) Because of the doctrine of Parliamentary supremacy, the only other forms of judicial review in the UK are for Acts that conflict with EU law, and the "declaration of incompatibility" under Section 4 of the Human Rights Act 1998.
In Canada, this has only really been a thing since 1982, when the Charter of Rights and Freedoms was enacted with the new Constitution. Any person can challenge a provincial or federal law if they think it violates some section of the Charter. If a judge rules that the law violates the Charter, it can still be upheld if the government can justify the violation as being reasonable and that it provides a greater benefit to society; otherwise, the law is struck down. However, in keeping with the British doctrine of Parliamentary Supremacy, section 33 of the Charter (a.k.a., the Notwithstanding Clause) gives the federal Parliament or provincial legislatures the option of invoking this section to shield unconstitutional laws from judicial review for up to 5 years and allow them to be enforced in that time. After 5 years, the law can be struck down if the clause is not renewed for another 5 years (this can be done indefinitely). This is typically considered a nuclear option though, due to the high political costs of using section 33.
Determination of scrutiny level
All laws discriminate. The speed limit discriminates against people who want to drive more than 70 mph on the interstate. Tax law discriminates against people who work, and those who don't feel like paying the government part of their salary. The question of judicial review, especially in cases that involve civil rights, is simply this: is the law in question one that the State can legitimately make? The State is given much leeway in laws that treat people equally with regards to all but the selected prohibition, even if that which is prohibited, restricted, or regulated seems frivolous.[note 1]
However, when the group targeted by the law is defined as a suspect class (that is, a class commonly targeted for social and economic discrimination, such as women, African Americans, or children) then Courts must use a more precise level of scrutiny to ask if the government has a compelling reason for the law, to ask if the ends can be achieved without out discriminating against the group in question, and, if the law is truly necessary yet still discriminates, has it been written in such a way that insures that the discrimination is as limited as possible.
- For example, many states have "blue laws" which state that certain stores cannot be open on Sunday or after 5 pm. The State does not need to provide justification for the law, other than proving that it was voted on according to the states procedural rules.