North Yorkshire County Council s planning committee saw a planning officer accuse elected member John McCartney of being "selective", before the the Osgoldcross division councillor repeatedly accused the officer of lying in the officers' report on Went Valley Aggregates' plan for a 9.7-hectare quarry extension to Went Edge Quarry, Kirk Smeaton, near Selby.
The row follows months of claims that numerous planning applications across the county have seen the authority's planning officers show favour towards large-scale developments over residential and environmental opposition.
Concerns over plans to have just one unitary authority covering the county reared again as the meeting saw the planning committee split, with members highlighting that those in favour of the controversial quarry scheme had the Yorkshire Dales and North York Moors on their doorsteps while those against it lived in an industrial area.
The meeting had heard the firm aimed to blast magnesian limestone to a depth of 30 metres over eight years before introducing a scheme to restore the area overlooking Yorkshire Wildlife Trust's SSSI Brockadale Nature Reserve, which features ancient woodlands and meadows, to grassland.
Dr Paul Simmons, of Brockadale Nature Reserve Supporters Group, claimed the scheme could damage plant growth, the hydrology of the area and leave a fine limestone dust over plants, reducing photosynthesis.
Members heard tens of thousands of visitors enjoyed the tranquility of the reserve which would be shattered by the extended quarry and it would have a catastrophic impact on the landscape and dozens of vulnerable and rare plants and creatures identified as being in sharp decline in Yorkshire.
Objectors said there was a sufficient supply of magnesium limestone in the county and the plan conflicted with the council's policy of stopping encroachment onto open countryside. They also suggested the site would not be restored, but instead would eventually merge with an industrial estate.
An agent for Went Valley Aggregates said there was "little or no risk" to the SSSI that could not be managed, and that objectors had not provided proper evidence for their concerns. He said the quarry had been operational for 50 years and the 300 flowering species of the SSSI and abundance of fauna, such as butterflies, were thriving.
The meeting was told the quarry currently employs 30 people and the extension would extend those roles for up to 12 years and counter claims there was a shortage of aggregates in the area.
Planning officers, who had recommended the scheme for approval, told the meeting hundreds of residents had objected to the plan and more than 1,200 people had signed a petition opposing the application. However, they then appeared to question the petition's significance by saying it had been signed by someone living in Iceland.
The officers, who have been repeatedly accused of backing development proposals which do not benefit local communities, then denied talking down the petition. They said they had intended to highlight "the width of the petition".
Officers added residents' concerns were understandable, but there were no material considerations on which the proposal could be rejected.
Coun McCartney questioned the officers' claims, saying that the council's own landscape architect had stated the scheme was not acceptable, but the officers' report had claimed he had approved it.
After officers appeared unable to produce evidence over that issue, Coun McCartney accused them of lying.
The committee's chairman, Coun Peter Sowray, said it was unacceptable for officers to be accused of lying and described the independent councillor's conduct as "disgraceful", but Coun McCartney said it was unacceptable that elected members were not being presented with the experts' conclusions.
He added: "North Yorkshire County Council likes to pass everything."
After hearing several hours of contradictory evidence over the plan, the committee approved the scheme.