Sue and John Gay have called Appin home for the past 35 years.
In that time the Gay family have dedicated their lives to protecting Macarthur's disease-free colony of koalas.
But now Mr and Mrs Gay, along with their daughter and grandson, face being evicted from their home.
Three years ago the state government announced that the state-owned property where the Gays reside would be transformed into parklands and koala habitat.
Mrs Gay said at the time they were informed by the Department of Planning, Industry and Environment (DPIE) that they would be able to remain at the Appin Road site.
"They told us originally that we would be able to stay here on a small part of the land in a caretaker capacity," she said.
"We have lived here for 35 years and to move at our age, with our health conditions would be detrimental - it would also mean splitting up three generations of our family.
"We will have to move unless the government overturns the decision and allows us to stay."
The family has been told by the NSW Civil and Administrative Tribunal (NCAT) they have until March 31 to vacate the property.
In an effort to keep the family in their home a petition has been launched asking the government to reconsider its stance.
"As tenants for the past 35 years the Gay family has voluntarily cared for sick and injured koalas at their own expense and are keen to continue," the petition reads.
"Ms Gay, president of 'Save Sydney's Koalas', was recently recognised by parliament for her efforts, and Wollondilly Council supports the family's ongoing tenancy."
However a Department of Planning spokesman said it was "incorrect to say the department informed residents that they could remain as caretakers - at no time has this commitment ever been made".
"The department has provided significant support for more than 12 months in assisting the residents to vacate the property," he said.
"This has included a four-month period to find new accommodation offered in January 2020, an offer to fund the removal of unauthorised structures built on the site and any remediation of the land that may be required as a consequence, a further offer to extend the tenants' occupancy through to September 2020 to provide more time to find alternative accommodation with the assistance of a real estate agent.
"The Department can confirm the real estate agent has contacted Mr and Mrs Gay on several occasions to offer assistance, but this offer was not taken up.
"The park has been designed with the conservation of koala habitat as a priority. But instead of fencing people out, we want to create a place where people and koalas can come together."
Ms Gay said she had dedicated her time to supporting conservation efforts, especially when it came to the region's koalas.
"My daughter is a licensed WIRES koala care and rehabilitation person so we have had koalas in our backyard for many years and the bushland at the back of the property is ideal for releasing them when they have recovered," she said.
"That resource will be lost if we have to move.
"We are very emotional at the moment."
The state government-owned land in Appin could be transformed into playing fields, a playground or water play park with allocated koala habitat areas.
Ms Gay said the space could be a great thing for the region.
"This could be a win-win situation for residents, the environment, tourism and the koalas," she said.
"We just want to make sure there is a place for these animals to get help."
To sign the petition, visit: parliament.nsw.gov.au/la/Pages/ePetition-details.