The European Union Habitats Directive includes measures to protect sites such as special areas of conservation and special protection areas from the effects of development. Before undertaking or consenting plans or projects likely to have a major impact on such sites, a public body as the "competent authority" must carry out an "appropriate assessment".
The competent authority can normally only let the plan or project proceed if this assessment concludes that development will not adversely affect the integrity of a site protected by the directive.
As an exception, however, the authority may agree to a plan or project that will have an adverse impact if there are no alternative solutions, the plan or project must be carried out for imperative reasons of overriding public importance and adequate mitigation or compensatory measures can be secured.
In April, the CJEU ruled on the People Over Wind and Sweetman case. The case concerned a proposed electricity cable serving a wind farm in the Republic of Ireland.
An assessment of the judgement published by professional membership body the Chartered Institute of Ecology and Environmental Management (CIEEM) said that it had "potentially significant implications in the UK, in that it appears to reverse the judgement in the Dilly Lane case".
In the Dilly Lane case, according to CIEEM, it was concluded that mitigation or compensation measures that were part of the project could be taken into account at the screening stage of a habitats regulations assessment.
If such measures are seen as capable of avoiding or offsetting the adverse effects of development on a site protected by the Habitats Directive, says CIEEM, then a finding of "no significant effects" could be made at the screening stage, and a full HRA assessment would not be required.
But, in the new judgement, the CJEU concluded the Habitats Directive "must be interpreted as meaning that, in order to determine whether it is necessary to carry out, subsequently, an appropriate assessment of the implications, for a site concerned, of a plan or project, it is not appropriate, at the screening stage, to take account of the measures intended to avoid or reduce the harmful effects of the plan or project on that site".
Last week, inspector Mike Hayden flagged concerns that Central Bedfordshire Council’s recently-submitted local plan could fall foul of the ruling.
In a letter to the council, Hayden said he had identified "an issue with the evidence base" of the draft plan "which may necessitate further work".
Hayden said that the implication of the People Over Wind judgement "is that competent authorities cannot take account of any integrated or additional avoidance or reduction measures when considering at the Habitats Regulations Assessment (HRA) screening stage whether a plan is likely to have an adverse effect on a [site protected by the Habitats Directive]."
Hayden noted that the council’s HRA screening report concluded that "some European sites were at risk from increased air pollution, disturbance and changes to water levels and water quality as a result of policies and allocations in the local plan, but that the plan’s policies provide sufficient mitigation, such that no significant effects are likely to occur, either alone or in combination".
Hayden said that, on the basis of this conclusion, the council's screening report "may conflict" with the CJEU judgement.
The inspector has asked the council if it believes the HRA is "legally compliant in the light of the judgement" and, if not, what further work the council believes "would be required to rectify this and what the timescale would be to complete and consult on that work".
A spokeswoman for Central Bedfordshire Council said: "Our local plan complied with the guidance and law at the time. However the EU judgment in mid-April has now changed the guidance.
"All local authorities who have recently submitted their local plans are being asked to review their habitat assessments in light of the new guidance. We are confident that this won’t adversely affect the overall progress of our local plan."
Central Bedfordshire Council voted to submit its local plan for examination in April, before the government's new standard method for assessing housing need comes into force, after officers warned that the new method would cause a 60 per cent rise in its homes requirement.