ANTONY STRATTON (R on the application of) v THE LONDON BOROUGH OF ENFIELD

The claimant challenged a delegated grant of planning permission for 17 Chase Side Avenue on the grounds of a material error of fact and insufficient reasons. The defendant conceded the substantive grounds but argued that substantive relief should be withheld under section 31(2A) of the Senior Courts Act 1981 or by the court's general discretion.

The court held that the officer had relied on an erroneous factual assumption (that the claimant's property had a bricks-and-mortar rear extension) which materially affected the assessment of neighbour amenity. The defendant failed to prove the high threshold in section 31(2A) because the contemporaneous decision documents did not show that permitted development rights or enforcement considerations had been in the officer's mind, and any assessment of the weight of a permitted-development fall-back would require planning judgment the court must not undertake.

The judge therefore declared the first permission unlawful but, exercising the court's ordinary discretion (not under section 31(2A)), declined to quash it because a later (second) permission had been granted and was unchallenged, rendering quashing academic.

Background and parties: The Interested Party applied for planning permission for a single-storey side and rear extension at 17 Chase Side Avenue. The claimant, owner of the adjoining property at 31 Riverside Gardens, objected, pointing out that the application plans incorrectly depicted a bricks-and-mortar rear extension at the claimant's property. The council officer nonetheless granted planning permission (the 'First Permission'). The claimant sought judicial review to quash the First Permission.

Procedural posture: The defendant accepted the substantive grounds of unlawful decision-making (material error of fact and inadequate reasons). The sole remaining issue was what relief should be granted: whether relief should be withheld under section 31(2A) Senior Courts Act 1981 or otherwise in the court's discretion. Meanwhile a later, larger permission (the 'Second Permission') was granted to the Interested Party; that permission was unchallenged by the time of the hearing.

Nature of the claim / relief sought:

• (i) The claimant sought quashing of the First Permission and associated relief on grounds including a material error of fact and inadequate reasons.
• (ii) The defendant accepted unlawfulness but sought to resist quashing, relying principally on section 31(2A) and, subsidiarily, the court's general discretion to withhold relief.

Issues framed by the court:

• whether the First Permission was unlawful (admitted);
• whether the defendant discharged the burden under section 31(2A) to show it was highly likely the outcome would not have been substantially different absent the conduct complained of;
• whether the court should nevertheless withhold substantive relief by exercise of its general discretion, having regard to intervening events (notably the Second Permission) and other equitable considerations.

Court's reasoning and conclusion: The court analysed the First Officer's Report and concluded the officer had relied upon a mistaken factual assumption that was pivotal to the amenity assessment. On section 31(2A), the defendant bore the burden of proof and failed to show that the outcome was "highly likely" to have been the same absent the error. Key reasons were (a) the contemporaneous decision paperwork contained no indication that permitted development rights were in the officer's mind, so any retrospective reliance on a fall-back would require the court impermissibly to undertake planning judgment; and (b) enforcement hypotheticals likewise were not part of the contemporaneous decision and could not reliably be used to meet the high statutory threshold. Although the court rejected the defendant's section 31(2A) argument, it exercised its general discretion not to quash the First Permission because the subsequent unchallenged Second Permission had overtaken the First, making quashing academic. The court therefore made a declaration that the First Permission was granted unlawfully but declined to quash it.

The court declared that the First Permission was granted unlawfully but, exercising its general discretion, declined to quash the First Permission because a later unchallenged permission had superseded it and quashing would be academic. The court rejected the Defendant's primary submission that relief should be refused under section 31(2A) Senior Courts Act 1981, holding that the Defendant had not proved it was "highly likely" the outcome would have been the same absent the error, and that permitting the court to assess the weight of a permitted-development fall-back would impermissibly involve it in planning judgment.