In 1967, Merioneth County Council granted planning permission for the development of 401 dwellings ("the 1967 Permission") on a site in Snowdonia National Park ("the Site"). Between 1967 and 1973, it made seven further grants of planning permission in respect of the Site, each of which departed from the scheme of development authorised by the 1967 Permission.
Gwynedd County Council became the relevant local planning authority in 1974. In 1987, it argued in proceedings brought in the High Court by Landmaster Investments Ltd, which owned the Site at that time, that the 1967 Permission had lapsed ("the 1987 proceedings"). The High Court rejected that argument, deciding that the development authorised by the 1967 Permission could still lawfully be completed at any time.
Snowdonia National Park Authority ("the Authority") became the relevant local planning authority in 1996. It made eight further grants of planning permission in respect of the Site between 1996 and 2011.
In 2019, Hillside Parks Ltd ("Hillside"), which now owns the Site, brought a claim against the Authority, in order to ascertain whether the scheme of development authorised by the 1967 Permission could still lawfully be completed. The Authority argued that it could not be, as development carried out pursuant to the additional permissions granted after 1967 was inconsistent with it. In particular, roads had been built in areas designated for houses, and houses had been built in areas designated for roads. This kind of argument was not made by Gwynedd County Council in the 1987 proceedings. Nonetheless, the High Court and the Court of Appeal allowed the Authority to raise the point and ultimately resolved it in the Authority’s favour. Hillside now appeals to the Supreme Court.

Mr Roberts suffered brain damage at birth in the Viersen General Hospital (AKV) in Germany in June 2000. Mr Roberts claims that this occurred as a result of the negligence of the attendant midwife, who was employed by the Soldiers, Sailors, Airmen and Families Association Forces Help (SSAFA). He also sued the Ministry of Defence (MoD), which will indemnify SSAFA against any liability.
SSAFA and MoD have brought a claim against AKV for contribution if Mr Roberts’ claim against them succeeds. The basis for this contribution claim is the 1978 Act. The parties agree that the law governing the contribution claim is German law and under German law, the claim would be time-barred. However, if the 1978 Act has overriding effect and if SSAFA/MoD can show that AKV is liable under it, their contribution claim will be in time.
The High Court considered this issue as a preliminary issue before the rest of Mr Roberts’ claim is decided. The High Court decided that the 1978 Act does have overriding effect and therefore SSAFA/MoD’s contribution claim against AKV is not time-barred. The Court of Appeal agreed. AKV now appeals to the Supreme Court.