There is much current discussion in planning circles about the case of Uniplex v NHS Business Services Authority a case from the European Court of Justice reported in January 2010. Although the case, challenging an NHS procurement decision, was brought under the Public Contracts Regulations 2006, the requirement for an action to be brought "promptly and in any event within three months" applied.
The case found that the requirement for such actions to be brought "promptly" did not ensure that the relevant Directive had been properly transposed into UK law. This was because the "promptly" requirement made the period, in which a challenge should be brought, uncertain. A claimant should be given the full 3 months.
This clearly has implications for cases of JR challenges to grants of planning permission. Although there is no "6 week rule" as such, advisers have tended to advise that actions brought after 6 weeks have gone by from the relevant decision (but still within 3 months) are at real risk of failing on promptness and the Courts have often sought to set the bar at a high level in planning cases because of the impact of a challenge on the rights of those with the benefit of the relevant planning permission.
However, note also the more recent case of R (on the application of Pampisford Estate Farms Ltd) v SSCLG. Here, the Court considered Uniplex and observed that it was not a case where the lack of promptness could have a significant adverse effect on other parties. In Pampisford, the Court came to the view that Uniplex "cannot as a matter of EC law overturn on its own the statutory basis of CPR 54.5" and found that the action, brought within 3 months, had not under the circumstances of that case, been brought promptly.
There is a further point of note in Uniplex which relates to the time when the 3 month period begins to run. In Uniplex the Court favoured the time when the claimant knew or ought to have known about the decision rather than the actual decision. This is at odds with the current position (which following the clarification in Burkett is that it is the actual grant of permission which sets the clock ticking) and, if it were to be seen as relevant in planning decisions, the point could have serious consequences.