Kevin McNamara (Lab) accused the Audit Commission of making unsubstantiated allegations in its damning corporate governance report into Kingston-upon-Hull City Council.
He tabled a series of House of Commons motions, attacking both the commission and its head Sir Andrew Foster, the latest of which brands the watchdog 'unprofessional', for not producing evidence of specific incidents of bullying (LGC, 29 November).
The commission itself has stood by its report, which it argues points to a culture of bullying rather than individual instances.
The MP suggested a neutral body, which could be the Local Government Association, could act as a mediator between the councillors and the commission.
'What has happened has been brutally unfair and runs against natural justice,' he told LGC. 'I'm keen that a remedy is found for this awful injustice that has been done to these councillors.'
Part of Mr McNamara's complaint is that allegations of bullying have not been referred to Hull's own standards committee, chaired by the academic Lord Norton of Louth.
But an Audit Commission spokeswoman said it would continue to resist pressure to reopen the issue of bullying, which she said would distract attention from improving services.
'We have repeatedly made the point that our inspection looked at the whole of Hull's corporate governance.
'It identified many important issues, all of which need to be addressed if services for the people of Hull are to improve. One such issue was that a culture of bullying had been tolerated.
'We have consistently stated that this issue must be looked into in the context of the whole report.'