Judicial review has two senses. In administrative law, it is the superior courts' supervision of officials, ministers and tribunals: did the decision-maker have the power, follow fair procedure, and act reasonably? This review of executive action exists across the whole common law family and enforces the rule of law daily.
In constitutional law, it is the stronger power to measure legislation against a supreme constitution and strike down what fails. The US claimed it in Marbury v Madison; Canada, Australia and India have it by constitutional design; the UK and New Zealand deliberately do not.
Both senses are at full strength: superior courts review administrative action (with the framework restated in Vavilov), and any court may declare legislation inconsistent with the Constitution of no force under s. 52.