However local State MP John Barilaro has warned the NSW Government may not be able to fix what he said was Council's problem.

Councillors held a workshop on Wednesday night to review their legal advice following widespread anger from many of the 860 affected ratepayers.

Mayor Tim Overall said he'd now convene an extraordinary meeting of Council next Wednesday night to address the issue, and move a motion to approach the minister and seek a resolution to the crisis.

"At this meeting, a Mayoral Minute will be tabled and it will include a recommendation that Council approach the Minister for Local Government to resolve the matter," Cr Overall said.

"The recommendation will also seek to put the 31 August payment deadline on hold until such time as advice is received from the Minister and that all affected property owners be formally advised accordingly.

"We are not expecting this matter to be solved overnight, and it may take two to three months to get a solution. During that time, all supplementary rates notices are on hold until further advice is received. It will not affect the normal annual rate payment cycle," he said.

Local member John Barilaro welcomed Council's attempt to abandon the unpopular invoices, but said there were no guarantees the NSW Government could fix the situation.

"Queanbeyan City Council has rowed up the creek and now it's my job to find them a paddle," he said.

"Whilst seeking the Minister's advice is a sensible approach, there are no guarantees that the NSW Government alone can resolve Council's problem.

"It is worth remembering that this unsatisfactory situation could have been averted had council elected to wear the cost of its mistake in the first place and refrained from re-issuing the rates notices," he said.

Meanwhile, Silva Avenue auto and boat mechanic David Hitchcock says he still can't believe the invoices - in his case a bill for nearly $11,000- were issued in the first place.

Council development regulations required the local mechanic to upgrade his 25mm water metre to a 40mm commercial metre when he built his workshop in 2004, despite the fact he has only one toilet and one sink in the building and say he uses "next to no water" at the site. However he said he had a verbal agreement with Council staff at the time of building that he'd continue to be charged the 25mm water access rate while he owned the site due to the low water use of his business.

"That agreement was honoured for 10 years and I was charged the 25mm rate, until I got this bill for 40mm water access backdated five years," he said.

"That's despite the fact there's nothing in the building that uses a 40mm pipe."

However a Council spokesman said any record of an agreement would have been documented on its records management system, and no such record existed.

"A number of properties in the industrial areas of Queanbeyan have been charged for a 25mm water and sewer connection, despite actually having a 40mm connection. This is why supplementary charges have been raised," the spokesperson said.

"Council's Development Design Specification D11 states that all industrial properties must have a minimum 40mm water and sewer connection. This is also stated in the notice of determination that is issued with approved development applications."

Mr Hitchcock said he'd seek to fight the charges, and would continue to work with an informal ratepayers group seeking to overturn the backdated charges. The group held their second meeting at John Bull St business owner Lisa Robinson's shopfront last night, and member Kim Morris told The Queanbeyan Age the group would continue to investigate options to challenge the invoices.