Legislation may set out express consultation requirements as part of the decision-making procedure. Failure to comply with such an express procedural requirement may leave a decision vulnerable to challenge.
In other cases the Court will infer a duty to consult, despite there being no express requirement in legislation. Such an implied duty to consult may arise:
- from an express promise made by the public authority to consult or from the public authority’s established practice (so-called procedural legitimate expectation), or
- in exceptional circumstances, where the public authority has not promised expressly or through established practice to consult, but where the impact of the authority’s previous conduct (e.g. in providing a particular service) on an individual or group is sufficient to give that individual or group reason to expect the policy to continue for their particular benefit for a reasonable period. In such a case a decision cannot lawfully be made in relation to that service unless the authority notifies the persons affected and consults (this is so-called secondary legitimate expectation) (R (on the application of Bhatt Murphy) v The Independent Assessor  EWCA Civ 755).