New South Wales Environment Minister Frank Sartor has joined the list of state Labor MPs who will not be re-contesting next year's election.

Mr Sartor today ended months of speculation with the announcement, giving his valedictory speech to Parliament.

He used the speech to condemn Justice David Lloyd who criticised one of his planning decisions.

"In my opinion the use of the expression land bribe, quote unquote, by Lloyd J in 133 was reprehensible," he said.

Mr Sartor becomes the 18th Labor MP to decide not to re-contest next year's election.

He was elected to the seat of Rockdale in 2003 and has held portfolios including Planning, Science and Medical Research as well as his current job of Climate Change and Environment Minister.

The Premier Kristina Keneally says Mr Sartor discussed his decision with her.

She has thanked him for his contribution, particularly as Planning Minister and for the work he has done as the Minister for Cancer.

Before coming in to Parliament Mr Sartor served as Lord Mayor of Sydney for nearly 12 years.