NSW Labor heavyweight Frank Sartor is reportedly preparing to stage a challenge against Premier Nathan Rees, allegedly with the backing of Health Minister John Della Bosca.
It is understood the former planning minister is unlikely to get the numbers but the Sydney Morning Herald reports senior party members are still keen to see Mr Rees challenged.
Other sources claim Mr Della Bosca is behind the push as it may put him in a position to take the top job, but he denied the claims yesterday.
"I am totally focused on the health portfolio and improving services for NSW during tough economic times," he was quoted by the Herald as saying.
"I do not support any moves against the Premier."
The State Budget is announced next Tuesday and parliament closes for winter recess on June 26.