JUDICIAL review (JR) is often talked about and feared, but rarely understood.

Put simply, it is a mechanism by which decisions made by public authorities can be challenged in the High Court.

The power to apply for a JR remedy is a prerogative which means that, in legal theory at least, it is exercised by the Crown on behalf of the applicant.

A review is fundamentally different from an appeal because it concentrates on the legality of the decision in question. In other words, it looks for a legal error in the way in which the decision has been taken rather than carrying out an assessment of the merits of that decision.

If there is no legal error, a JR challenge will not be successful.

Equally, the judge does not make a new decision to substitute that of the original decision-taker.

The object of the review is either to quash the decision (and remit it back to the decision-taker for a new decision to be made) or to order the decision-taker to do or refrain from doing something.

Typical grounds of review are where a public authority has stepped outside permitted procedure, has failed to have regard to a relevant issue, has had regard to an irrelevant issue or has acted irrationally.

Local authorities, for example, must operate within their statutory powers and, in many cases, are given discretion as to how or whether they exercise a statutory power. That discretion must be exercised reasonably. If not, it is potentially open to challenge by JR.

JR can be a very expensive means of redress because it must be begun in the High Court – in London, Leeds of Manchester – and often necessitates specialist legal advice and drafting.

The first step is to make an application for permission to apply for JR, usually decided upon the case papers without the need for a hearing.

Permission must be granted for the application to proceed to a full hearing in court.

JR proceedings must begin not more than three months from the date of the decision to be challenged, and in some cases six weeks..

■ Neil Carter is a solicitor at BHP Develop specialising in planning and local government law and can be contacted on 0191-221-0898.