The deed states the council, shall "for ever hereafter hold the said piece of land as a Borough Reserve upon trust that the same may be used as a Public Park Children's Playground and Public Recreation Ground."
Taylor said the petition had received around 100 signatures since they started door-knocking the residents on Thursday, and so far no one had refused to sign.
He said the draft plan neglected the western end of the park, and he feared that while council currently had no plans to sell the park, it would let its condition deteriorate until it had an excuse to sell it.
The group said the draft plan also over-exaggerated issues the park had with security and rough sleepers.
"I didn't recognise the park they were talking about," Koenders said.
A Hastings District Council spokesperson said people can submit of the draft plan, with submissions closing on January 18. People can also choose to speak on their submissions at hearings, which are expected to happen in mid-February.
They said if council and the community decided to retain the right to sell the northwest end of the park, council would need to follow a complex, legal process to see if the sale can be implemented.
"This will include meeting all legal requirements and obligations, including consideration of the terms of the gifting from the descendants of the original donor.
"All of these are issues that would have to be worked through in due course, but the first step is to see what the community thinks about it and that is the process that is under way."