But it is understood the current General Secretary (and the first woman to hold the job) Kaila Murnain, wants to fight a NSW election campaign before she considers moving into political candidacy.

Traditionally the spot has gone to the state party's general-secretary – Dastyari was a former NSW Secretary, as were his senate predecessors Mark Arbib and Matt Thistlethwaite.

"I respect the ALP's nomination process and will work within it to earn the backing of our party's members and the affiliated trade unions."

"Over the coming days I will be speaking with rank-and-file members of the NSW ALP and affiliated trade unions to the Labor Party to seek their support.

So the ultimate decision was to be made by Murnain, in consultation with the Right-faction affiliated unions, such as the Australian Workers' Union, the Shop, Distributive and Allied Employees' Association, and the Transport Workers' Union.

Sheldon was the unions' preferred choice, with his deep passion for campaigning and his pugnacity. The spot was understood to be his if he wanted it, but according to one Labor insider, it was unclear if Sheldon was interested in being a member of parliament, and if he was, he would be more likely to hold out for the next general election, when a plum six-year senate spot will be available on the NSW Labor ticket.

At a press conference on Wednesday about recent fatal truck crashes, Sheldon said he had not put his name forward "at this point" to make a "formal nomination". Later he said: "I haven't made a decision about my nomination, potential nomination, as yet."

Moriarty is seen as a solid performer but not frontbench material, and is more likely to be offered a seat in the NSW upper house, insiders say.

Which left Keneally as the last woman standing. AAP reported on Wednesday she was facing pressure from "influential unions" not to stand, and even her allies say she will be open to the sorts of attacks made on her during the Bennelong byelection - that she was elevated to the NSW premiership with the support of some of NSW's most notoriously corrupt politicians, Eddie Obeid and Ian MacDonald.