New South Wales Labor MP Barbara Perry has announced she will not recontest her seat of Auburn in Sydney's west, in order to give new state Opposition Leader Luke Foley a clear run at a Lower House seat.

Ms Perry had been embroiled in a bitter preselection fight with another candidate, Hicham Zraika, who she had accused of branch stacking.

But after Mr Foley became leader on Monday, the ALP cancelled that preselection and opened a fresh contest to give him a chance to nominate for the seat.

Ms Perry is now officially endorsing Mr Foley's nomination.

"I always knew the incredible honour I have had to represent this community would come to an end one day," she said.

"I've long hoped that the man standing next to me would be my successor, Luke Foley."

After previously saying she would not withdraw her name from the preselection, Ms Perry denies she has been pushed.

"No I haven't. I am doing this willingly. It's my own choice," she said.

Ms Perry has held various portfolios since becoming the member for Auburn in 2001.

Mr Foley who had insisted on a rank-and-file preselection to allow branch members to have their say, denied he was parachuting into the seat.

"It is not undemocratic for a member who has long had a succession plan in place to sit down with her preferred successor and talk about a transition," he said.

Mr Foley, an Upper House member, was elected Labor leader after the sudden resignation of John Robertson after revelations he signed a letter to a government department on behalf of Sydney siege gunman Man Haron Monis.

Nominations close on Thursday.