Misha Zelinsky announced on Thursday night that he was withdrawing from the preselection contest in the seat held by Labor MP Sharon Bird, who will retire from politics at the forthcoming federal election.

Mr Zelinsky, the assistant national secretary of the Australian Workers' Union and secretary of the Australian Labor Party's national policy forum, revealed he would nominate last month, just hours before cut-off.

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But in a statement posted on social media, he said most Labor members did not support his bid.

"As I have had discussions with local Labor members, I have encountered encouraging support for which I am grateful... However, it's become clear that the majority of Labor members believe now is not the time for me to run for federal parliament," Mr Zelinsky said.

"A ballot would be a needless distraction from the upcoming election fight."

His decision leaves the door wide open for Alison Byrnes, a long-time staffer to Ms Bird who has worked in the Labor party for some 30 years.

Mr Zelinsky said he wished Ms Byrnes "the very best".

In response, Ms Byrnes said she appreciated Mr Zelinsky's well wishes.

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"I similarly convey my best wishes to Mr Zelinsky on his future endeavours," Ms Byrnes said.

"We certainly share a desire to work for the election of an Albanese Labor government."

She also said she was overwhelmed by the strong support she had received since announcing her candidacy for preselection.

It is understood Labor's administrative committee will likely undertake its formal endorsement processes next Friday.

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