Mambo Wanda Wetlands Landcare Committee chairman Walter Lamond said he was “completely taken aback” when he saw newly erected signs advertising the land – lots 560 to 566 at Port Stephens Drive –  for online auction closing June 9.

He’s not alone. The Greens have called for the government to transfer the land to the volunteer committee, while Port Stephens MP Kate Washington has asked the government to stop the sale.

“We don’t believe it should go ahead,” Mr Lamond said. “The government parcel is within a significant portion of the western side of the wetlands.

“Within the 179 hectares of wetlands we have 300 species of vegetation, 30 types of native mammals, 18 types of frogs, 20 different reptiles and 140 different birds.

“It’s E2 Environmental Conservation Zoning but we believe if somebody were to buy it, they would start the process to have it rezoned to another category, which would offer less protection for the environment.”

Knight Frank Newcastle agent Nick Lane, who took the government’s 60,000 square metres property to market for the first time on Saturday, said agents had been upfront with prospective buyers about the restrictions of the “very tightly regulated” zoning.

“If you read through the provisions there are very few things you can do of a commercial nature,” Mr Lane said. “Eco-tourism is probably the pick of them as to what you could do with it, there’s not much scope there.

“We’ve had some calls from parties wanting to inquire about potential future use, thinking commercial or development. But once they realise the restrictions, that’s tempered their expectations.”

However Port Stephens MP Kate Washington, who said the region relied on its environmental beauty and pristine nature for tourism, echoed Mr Lamond’s concerns and pointed the finger at the council, which she said did “not have a good track record of environmental protection” and may approve an unsuitable development or a zoning change.

“We see all sorts of things happen in the interest of development, over the interest of the environment,” she said.

A Port Stephens Council spokesperson said any possible move by a future owner to change zoning would require a detailed council assessment and formal public consultation.

“Considering the values identified within the site, a rezoning would also require consideration and endorsement from the state government,” the spokesperson said. NSW Greens MLC Dr Mehreen Faruqi and Greens candidate for Paterson John Brown have called instead for the government to withdraw the land from sale and formally transfer it to the Mambo Wetlands Reserve.

“It has been cared for by volunteers for many years on the assumption that it is an integral part of the Wetlands Reserve, and their dedication and hard work must not be betrayed,” Mr Brown said.

Ms Washington said the committee’s long-term care for the land only highlighted the “unusual” timing and method of the sale. She and the council confirmed they had not received any prior or official notice the land had been listed.

“Without consultation, the signs have gone up overnight,” she said.  “With a short time frame and the unusual form of sale, it suggests a purchaser has been earmarked by the government and the community has been kept in dark.”

A Department of Education spokesperson said the government was selling the land by competitive process on the open market, “as mandated by NSW Treasury guidelines for surplus department land”.

It purchased the land “a number of years ago” and said it was“aware of the conservation value”.

“The department regularly buys land for the provision of school infrastructure and sells land if no longer required,” the spokesperson said. “The department has determined that it will not develop the site for a future school and has declared it surplus to educational requirements.”

Ms Washington said the community would welcome more schools elsewhere in the area. She said Tomaree High was built for 1100 students but currently had more than 1200.

“We need to have a discussion about what plans they have for meeting future education needs for students on the peninsula,” she said.

Ms Washington has requested an urgent briefing this week from the ministers for finance and education.

The government is also selling surplus land at Fullerton Cove and Croudace Bay. 

The Fullerton Cove property is about 69,000 square metres across two individual lots on Fullerton Cove Road and is zoned Rural Landscape and marketed as hobby farm land.

The Croudace Bay property is about 67,500 square metres on Parklea Avenue and is zoned Public Recreation and marketed as suitable for a childcare centre, subject to council approval.

Newcastle MP Tim Crakanthorp described the Fullerton Cove land as “achingly close” to the Williamtown RAAF base contamination red zone. 

“Do they know something we don’t?” he asked. “Any sales of land in the area should be placed on hold pending the outcome of the Williamtown contamination investigation.

“We also need the government to guarantee that  the land is not contaminated.”

The department spokesperson said the sale was “not connected” with the pollution.

Knight Frank is taking all three government properties to auction on June 9.