Mr Buckley, a member of the ALP's Valentine branch, is the party's only preselection mayoral candidate, but is not a current councillor.

He served as Shortland MP Jill Hall's campaign director for last year's federal election.

Mr Buckley said he would not comment until after today's preselection ballot.

A letter that Mr Buckley sent to party members, seen by The Herald, said local Labor MPs had encouraged him to contest the election.

He said it would be difficult to unseat Mayor Greg Piper.

"I do not underestimate the extent of the challenge; given your support, I'm confident it can be done."

Labor has not held the Lake Macquarie mayor's position for 15 years.