Judicial review is the way you challenge a public body on its decision. For judicial review, the defendant must be a public body and the claimant must have a ‘sufficient interest’ in the outcome of the decision to be given standing (be able to bring the case). This usually means that the outcome of the decision must directly affect the claimant. However, pressure groups are sometimes given standing. Some examples of judicial review cases are; challenging your local authority on its decision to deny you planning permission; or as the Good Law Project have been doing, challenging the Government on its decision to award a contract to a particular company.
Judicial review cases must also be a last resort and the claimant must obtain permission of the Court to commence proceedings.
Judicial Review cases are heard in the Administrative Court of the High Court. The Court will be concerned with the legality of the decision made and not with the merits of the decision. The question is not whether the decision itself was correct, but whether the powers given to the decision-making body were used correctly.
Judicial review proceedings must be brought on one or more of the grounds set out in the case, Council of Civil Service Unions v Minister for the Civil Service  AC 374. The grounds are as follows:
The decision maker must correctly understand the law that regulates its decision-making power and must correctly apply it. If they fail to do so the decision may be beyond power and therefore unlawful. A recent example is Matt Hancock failing to comply with legal procurement and transparency requirements when awarding Covid-19 contracts. Another example is when the decision maker unlawfully delegates its decision-making power to another.
This is when a decision is “so outrageous in its defiance of logic or of accepted moral standards that no sensible person who had applied his mind to the question to be decided could have arrived at it”. (As stated by Lord Diplock in  AC 374 above).
This is when the decision maker fails to adhere to basic rules of natural justice or fails to act with procedural fairness towards the person who will be affected by the decision. This includes when an act gives a Minister the power to legislate by way of statutory instrument but stipulates the procedure to be followed and they fail to follow it, such as a requirement to consult with those affected by the decision. Natural justice includes the right to a fair trial; a right to be informed; a right to be heard; time to prepare; a right to reasons; and the rule against bias. A recent example is the High Court finding that Michael Gove’s decision to award a Covid-19 contract was tainted with “apparent bias”.