Long-serving Northern Territory MP Warren Snowdon has vowed to fight for his political life after he was dumped by the Labor Left faction he helped set up.
Mr Snowdon, who was first elected in 1987, was told on Thursday night he had been disendorsed and the Left would back another candidate for the federal seat of Lingiari.
Former Richmond AFL player Joel Bowden, 39, is shaping as a possible replacement.
When asked on Friday whether he would intervene in the preselection, federal leader Bill Shorten said "if if gets to it" but that he supported Mr Snowdon.
Mr Snowdon, 68, had been regarded as in danger of losing preselection for a while and things came to a head at last week's Labor conference in Darwin.
Several unions, led by CFMEU Queensland secretary Michael Ravbar and including the MUA and United Voice, unsuccessfully tried to unseat Labor NT secretary and right-wing faction member Kent Rowe.
At a dinner that night, Mr Snowdon strongly criticised the push as an attempt to "humiliate and bully" and he was involved in a verbal stoush with a young union organiser before a walkout by the Left.
The faction's response to dump Mr Snowdon and another five people is regarded as payback.
Mr Snowdon was elected to the seat of Northern Territory in 1987 to 1996 and 1998 to 2001. After a redistribution, he was elected to the seat of Lingiari, which represents most of the NT excluding Darwin.
He will rely on about 160 Labor members to preselect him in the next couple of months.
"These people need to understand I've had 11 elections, the people that vote in preselections for the best candidates in the Northern Territory are the rank and file voters, it is up to them," Mr Snowdon told AAP.
"People that live in Brisbane have no role, the Left should not be subject to the direction of external forces outside the Northern Territory.
"Members of the party and the left in NT like me thought what was being done was inappropriate, unfair and unreasonable and there is general dissatisfaction by many rank and file members of the way the Left has been functioning."
He said he would be part of a new Left faction being set up.
Mr Snowdon accused his party opponents of damaging the ALP's federal election chances.
"Unseating the Turnbull government is what we should be concentrating on and adequately representing the people of the Northern Territory. This is a sideshow," he said.