There has been much debate about the changes to the rules on judicial review of planning decisions.

In summary, the changes shorten and clarify the time within which proceedings for judicial review can be brought, and prevent the pursuit of claims that the court assesses as having no merit in being pursued. On the whole, the revisions, which came into effect at the beginning of this month, have been supported by the development industry and should also be welcomed by local authorities seeking administrative certainty.

Judicial review is not limited to the planning sphere. The changes, however, relate only to claims involving decisions made by the secretary of state or by local planning authorities under the planning acts and to claims involving procurement issues. One key change is that the claim form for planning matters must now be filed no later than six weeks after the grounds for challenging a decision first arose.

Previously, the requirement was that the form be filed "promptly" and in any event no later than three months after the grounds for a claim arose. The removal of promptness as a requirement pre-empts a traditional ground for argument by lawyers acting for authorities on the receiving end of claims. It responds to European Union law rulings and to suggestions that the requirement breached the European Convention on Human Rights, because the definition of "prompt" was not clear or certain.

What is puzzling, however, is that the new rules refer to local planning authority "decisions" as well as the time at which the "grounds to make the claim" first arose. This might have been unintentional, but there must be a fear that it will lead to arguments that the six-week period might start earlier than the date of the decision notice - for example, when a committee decision was made or a committee report published. This is unhelpful, not least because the House of Lords' decision in R (Burkett) v London Borough of Hammersmith and Fulham (2002) was thought to have made it clear that the date of the decision notice was the event from which time ran.

There are other potential consequences. The pre-action protocol on judicial review set out in the Civil Procedure Rules requires, in effect, that notice of potential claims is given to planning authorities by letter and that they be given 14 days to respond. Within a six-week overall timescale, this entails pretty fast working by all parties. The protocol has not been updated. It acknowledges that pre-action letters might not be appropriate where shorter time limits of less than three months apply, but still asks parties to "attempt" to comply.

It will be interesting to see what future decisions emerge on these procedural points. It would be a shame if unhappy drafting introduced new uncertainty.

This article appeared in Planning Magazine, 12 July 2013