Councillors voted on Monday night to endorse a submission to the Independent Pricing and Regulatory Tribunal arguing the council's viability as a stand-alone entity.

The submission was in response to a Independent Local Government Review panel report in January 2014, recommending Lake Macquarie and Newcastle councils merge to form a "super council" for 390,000 residents to save money and resources.

The Lake Macquarie council's submission argued these changes were not in the best interests of its 200,000 residents.

"The region is stronger with two large councils that have different, and complementary, expertise," the submission said.

"The merger will create a weaker organisation, and come at considerable expense to the residents of Lake Macquarie.

"[Lake Macquarie council] has already developed a successful blueprint for financial, economic, social, and cultural sustainability based on a solid foundation of community engagement."

Cr Brian Adamthwaite said the submission highlighted the council's sustainability.

"Hard data proves, certainly to us and I would hope to the independent observer, that we are fit for the future," Cr Adamthwaite said.

Lake Macquarie council has also formed a back-up plan with Gosford City Council should the NSW government reject their preferred options to remain stand-alone councils.

The proposal would see Lake Macquarie council extended south to Sparks Road at Warnervale, and Gosford council extended north to the same point.