The Planning and Compulsory Purchase Act 2004 requires a regional spatial strategy (RSS) to be put in place for all regions except London. RSSs are the starting point for the consideration of planning applications and local authorities must prepare Local Development Frameworks which are in accordance with the RSS.

In City and District of St Albans and Hertfordshire County Council v Secretary of State for Communities and Local Government, the councils challenged the East of England RSS under which green belt land was to be released to housing.

The councils challenged the RSS on the basis that no adequate strategic environmental assessment (SEA) of the RSS had been carried out. The councils argued that the Secretary of State had misunderstood the implications of the shift from the old local plan system to the broader regional focus brought about by the introduction of the regional system. The SEA regime had not been introduced in tandem with the RSS and the Secretary of State had not worked down to the level of environmental assessment detail required by the SEA.

The court quashed certain policies in the East of England plan. The effect is that Hertfordshire's method of achieving its housing targets will need to be reassessed.