A report in the Sydney Morning Herald on Wednesday quoted an unnamed Wollongong ALP member who claimed there had been "lots of head office dirty tricks" in a bid to secure Ms Hay's preselection.

The source said that a head office "operative" had pressured and threatened them in regards to "future careers and political aspirations" if they continued to support chief operating officer at the University of Wollongong's Australian Institute for Innovative Materials Paul Scully in the ballot on December 6.

Wollongong councillor Ann Martin is also a candidate for preselection.

Ms Hay denied she was part of the ALP party machine and said she had always been a grassroots politician who relied on the support of local members.

"This is a distraction," she said. "There are no high-flyers out there supporting me. I am a grassroots candidate and would like that preselection to take place without interference.

"I have sought no assistance of anyone outside this area. I would like the rank-and-file preselection to take place in a fair and just way."

The report claimed ALP head office was "pulling out all stops" to ensure Ms Hay survived the challenge.

However, NSW ALP general-secretary Jamie Clements said no-one from his office, as far as he was aware, had contacted any member of the Wollongong branch regarding preselection.

"This is a rank-and-file preselection," Mr Clements said.

"Noreen has not asked me to do anything and no branch member has asked me for my view."

However, Mr Clements said that he had spoken with Mr Scully.

"Candidates for preselection talk to me all the time," he said.

"It's a pretty big deal to try to knock off a sitting member and he knows that.

"I haven't encouraged him. I suppose you could say that in not encouraging him, I have discouraged him.

"He knows he's doing this off his own bat. He's challenging a sitting member and I'm not getting involved with that."

Mr Clements said he had not spoken with Cr Martin about her candidacy.

Mr Scully declined to comment.