But Maitland MP Robyn Parker said representing the people of the seat of Maitland had always been her top priority.

"The people of Maitland entrusted me with the honour of representing them in the NSW Parliament," she said.

"They elected me to be a fearless advocate for our community and that has always been my priority.

Ms Parker said she was proud of her achievements as minister for the environment and for heritage.

"It has been a privilege to serve as the minister for the environment and minister for heritage over the past three years. I am extremely proud of our many achievements," she said.

"These have included the establishment of the Environment Protection Authority as an independent environmental regulator, the creation of nine new national parks and reserves, ground-breaking approaches to threatened species conservation, record investment in hazard reduction to protect life, communities and our parks, record visitation at our national parks and gardens and the transformation of the way we deal with waste and recycling."

And she had a list of people she wished to thank for their support.

"Thank you to the many staff who have supported me at the EPA, Office of Environment and Heritage, the National Parks and Wildlife Service and across our Trust's, parklands and gardens," Ms Parker said.

"The passion and dedication you bring to your work has been an inspiration to me as I have worked with you across the state."

She urged her colleagues to be mindful that good policy, integrity and the well-being of the community should come first.

Ms Parker and Upper Hunter MP George Souris, a senior minister in charge of the hospitality and racing portfolio, have lost their positions to allow for some new faces, including Pittwater MP Rob Stokes, Castle Hill MP Dominic Perrottet, Wollondilly MP Jai Rowell, and Nationals MPs Troy Grant and Paul Toole.