The report by the Local Government and Social Care Ombudsman, published this morning, finds fault with North York Moors National Park Authority (NPA) for the way it adopted the policy and for not properly advising its members of the legal and administrative basis for the decision to do so.
However, the NPA has said in response that it will "probably" reintroduce the charging system, having suspended it in the wake of the watchdog’s investigation.
The probe was launched after a couple complained that the NPA had charged them for enforcing a planning notice.
North York Moors NPA adopted the policy of charging a proportion of enforcement costs to those who failed to comply with the terms of an enforcement notice in 2014, the ombudsman report says.
In introducing the policy, the report notes, it relied on section 93 of the Local Government Act 2003, which allows authorities to charge for certain services.
But it "had taken legal advice which did not identify any legislation or case law to support the introduction of charges to cover enforcement action," the report adds.
In 2015, the authority advised members that it no longer considered the 2003 Act as a suitable framework, but also said there was "no statute or case law that suggested a planning authority could not seek to recover costs of enforcement action," the ombudsman found.
"In making policy decisions, authorities should show a level of evidence reflecting the importance of the issue, and I would expect it to be meticulous for a decision as contentious as charging for planning enforcement," said the ombudsman, Michael King.
"In this case, North York Moors NPA’s decision was based on an inconclusive legal opinion and did not take into account all the relevant factors.
"Rather than a robust, risk-based decision it appears the authority has sought to justify a desired policy objective on limited and uncertain grounds."
The ombudsman’s report notes that the authority has now suspended the charging scheme, cancelled the charges made under it and issued refunds to those who have made payments.
It orders the authority to apologise to the complainants "for not properly considering the basis of the charge it sought to make and for not explaining the basis for that charge".
Should the authority seek to reintroduce the policy of charging for enforcement action it "should ensure it properly considers the basis for making a charge," the report adds.
NPA chairman Jim Bailey said the authority was "surprised and disappointed" at the findings and that authority members "believe they have sufficiently considered the legal basis of the scheme, including advice of a local authority barrister and specialist QC".
"Do we intend to re-introduce the cost recovery scheme? Probably, yes," said Bailey.
"The adoption and running of the scheme brought significant public benefit and the ombudsman does not conclude that the scheme was unlawful, but recommends the steps that need to be taken should the authority seek to reintroduce such a scheme."