Duty to co-operate
The Localism Act 2011 created a legal duty requiring public bodies to cooperate on planning issues that cross administrative boundaries. Local authorities are expected to demonstrate evidence of having co-operated with a range of bodies (e.g. neighbouring councils, service providers and statutory undertakers) to enable the delivery of sustainable development. Furthermore, local authorities are required to document the outcome of such co-operation and to identify what has been dealt with and how, as well as any unresolved issues.
Detailed Statements of Common Ground and Memorandums of Understanding were agreed in preparation of the Arun Local Plan (2018). Since that time, comprehensive co-operation has continued with neighbouring local authorities and all key stakeholders across the sub-region.
The statutory Duty to Co-operate in English planning has now been revoked (effective 25 March 2026). It will be replaced by a new system under the Levelling-up and Regeneration Act 2023 that focuses on a 'Requirement to Assist' and stronger regional planning. While the legal duty is gone, the Council will still need to demonstrate and evidence effective collaboration and engagement, particularly on unmet housing needs. Further detail will be forthcoming as a new Local Plan is prepared.