The council's sale of the 42.25-hectare Tullimbar site will see $13 million put towards the controversial hub project, which is valued at $57 million.

However, earlier this month, Shellharbour councillor Peter Moran said the fact the property had been sold through "a put and call option" meant finances would not necessarily be available when they were required by the council.

The Stop the Hub group said questions that needed answering included what the timeframe was for settlement on all of the Tullimbar land and what would happen when payments for construction of the hub fell due but insufficient money was available to fund the construction.

Shellharbour Mayor Marianne Saliba said a "put and call option" was a method used by developers where they subdivided a parcel of land, sold it, then used the proceeds to fund the next subdivision rather than buying the whole site in one transaction.

"In our case, if at any time the sale falls through, the land remains ours to sell," Cr Saliba said.

She said council staff were preparing a report to councillors on the financial implications. The council will be given final advice in April.