Milton Keynes Council last year commissioned an independent review into its handling of plans to build a warehouse in the Blakelands area of the new town.
The local authority had granted permission for the building in January 2018 but accidentally omitted 14 conditions from its decision notice. Results of the independent review were due to be published in October last year but are yet to be made public.
Local campaign group the Blakelands Residents' Association has claimed that the mistake with the planning permission is evidence of “clear systemic issues and failings” at the local authority.
The association said it has made a criminal complaint of alleged misconduct in public office against the council. Thames Valley Police confirmed last week that it is looking into the allegations.
Blakelands Residents' Association has called on housing secretary Robert Jenrick to launch an independent investigation into the allegations - and has now received backing from the town’s two Conservative MPs.
Iain Stewart, MP for Milton Keynes South, said: “I am deeply concerned by these allegations and they must be thoroughly investigated. The Labour-run council wants massive housing expansion in Milton Keynes. How can we have any confidence that this would be done well if there is truth in these allegations?”
Ben Everitt, MP for Milton Keynes North, said: “My team get a huge amount of correspondence relating to Milton Keynes Council's planning department, including the Blakelands warehouse and other controversial developments.
“It’s clear that there are concerns of prevailing failures in the planning service and I hope we can swiftly get to the truth of the matter, because this is really important to local people.”
The call for an investigation has also been backed by John Bint, planning spokesman for the council's Conservative group and a former chair of its development control committee.
“Given the range of concerns raised about failures across all aspects of the planning service, by residents and councillors alike, I fully support the request for an independent inspection into Milton Keynes Council’s planning department," said Bint.
Bint said he believes any alleged failings were likely to be a result of management problems at the local authority. “I think planning officers go to work committed to doing a good job", he said.
“When you have what appears to be systemic problems, then I think it is overwhelmingly likely to be either a problem with systems or procedures or with skills, training and confidence. Both of those I regard as being management failures rather than the responsibility of the person who makes the mistake.”
Milton Keynes Council was asked for comment on the latest criticisms but had not responded at the time of publication.
Asked last week about the police investigation into allegations of misconduct, a spokesman told Planning: "An independent review of this planning decision is under way and the council will consider and respond to the recommendations made following completion of the review."
A letter seen by Planning last week from the council's chief executive, Michael Bracey, to the residents' association stated: "We acknowledge that improvement is required in our planning service. That is why we have set up a planning improvement board. The work of the board is now well under way and progress is being made."
Elsewhere, the letter added: "Finally, while I am very concerned about the allegations you make about misconduct in public office, it is not for me to comment on a matter that has been formally passed to the police. They will decide if there is a case to investigate or not."