Labor MP Andrew Giles with Opposition Leader Bill Shorten at Labor's national conference in 2015 Credit:Alex Ellinghausen Labor's National Left faction met on Monday evening to discuss Senator Marshall's threat to Mr Giles' pre-selection and according to a Labor MP who attended the meeting, there was "a lot of unhappiness, and a view that it is up to Bill [Shorten] to squash this". Another Labor MP told Fairfax Media on Monday that Mr Shorten's decision to back his close friend and political ally, Ms Kitching, for the Senate was a "captain's call" that had shocked MPs across the Left and Right. Senator Marshall is a close ally of Victorian Labor Left powerbroker Kim Carr. The pair led a split from Labor's national Left faction and formed a new "industrial" Left after the July election - a move that saved Senator Carr's frontbench spot but cost Senator Marshall his position as deputy president. He told Fairfax Media on Monday that Mr Giles, who joined Parliament in 2013, "was a very bad fit for Scullin as the Labor member and there is a mood for change in the branch. I've been talking to lots of people in Scullin."

Labor health spokeswoman Catherine King with Opposition Leader Bill Shorten. Credit:Alex Ellinghausen In addition, Senator Marshall said that "many of the key players in the Victorian Left believe he [Mr Giles] has been disloyal" by aligning himself with the national Left, led by NSW MP Anthony Albanese and South Australian MP Mark Butler. "Am I organising a contest in Scullin? Yes, I am." He would not say who his preferred challenger for the seat would be and did not know who was responsible for circulating a dirt sheet circulated to Labor members in Scullin that called for Mr Giles to be replaced. Mr Shorten's decision to back Ms Kitching (pictured) to replace Stephen Conroy has shocked Labor MPs on the Left and Right. "He lied about the strategy to knock off Kim, there is disenchantment with Andrew and I believe he will face a preselection challenger. No one has an entitlement to their position, the purpose of the rules is that members are free to challenge for these positions."

A recent increase in Senator Marshall's visits to Ballarat, where he is the Labor duty senator, has not escaped people's notice either. Ms King, like Mr Giles, aligned herself with the National Left during the contest over the Labor frontbench. Senator Marshall told Fairfax Media that "there is discontent in Ballarat, too" about Ms King's decision to back the failed push to demote Senator Carr. "I've haven't heard anyone tell me that they want to challenge Catherine, but we are a long way our from preselections at this time," he said. Asked if he would support a challenge to Ms King, Mr Marshall said: "That's a possibility but it's not on my radar at this point in time". He dismissed suggestions that there could be a challenge to Labor frontbencher Jenny Macklin, and that he could be involved in such a move, because "it's now well known that she is retiring".

A spokesman for Ms Macklin dismissed any suggestion she was set to retire. The anonymous dirt sheet targeting Mr Giles was sent to all 950 members of his Scullin branch last week. It excoriated Mr Giles for failing to move from his inner city home in Clifton Hill to his outer suburban electorate and accused him of lying about his plans to move. "When my mates' jobs are going overseas and I can't get full time hours after being laid off at Ford, I don't want to hear he cried in Parliament about gay marriage - I want him to cry and fight for us, our jobs and our ability to put food on the table for our families," the dirt sheet said. "Enough is enough. We need a real Labor member to fight for our Labor values in Scullin." Senator Marshall said he was aware of the anonymous dirt sheet but did not know who was responsible for it.

Comment was sought from Mr Giles, Ms King and Mr Shorten's office. Follow us on Twitter Follow James Massola on Facebook