A former Country Liberals campaign manager says he has resigned from the party over the Mills Government's budget decisions.
Professor Don Fuller managed Country Liberals candidate Francis Xavier's election campaign last year, leading him to a 16 per cent swing and narrow win in the seat of Arafura.
Professor Fuller says the Mills Government did not adequately consult the community before introducing significant price hikes for power and water.
"A lot of us were trying to talk to senior people in the community and to put our views forward but were rebuffed," he said.
"And there wasn't a lot of avenue available to many people."
He says the Chief Minister Terry Mills has failed to deliver on his promises to the public.
"When he moved to do things quite differently, people have felt let down and they've felt deceived and therefore they are angry."
He says voters will punish the Government at the next election for the significant utility price hikes.
"Darwin people in my experience just don't forget easily.
"They remember and they are proud to remember often."
The ABC has obtained an email sent by Country Liberals party treasurer Graeme Lewis in which he says the party is better off without Mr Fuller, whom he describes as a treacherous man with a limitless ego and pickled brain.
Mr Fuller is considering his legal options regarding the email, which was copied to other senior Government officials.
Mr Lewis has declined to comment but Government advisers say the dispute is nothing more than sour grapes from Mr Fuller, who wanted a government job and did not get one.
The Acting Chief Minister Robyn Lambley says Mr Fuller is disillusioned and disgruntled.
"I think Mr Fuller needs to take a deep breath and remember why he voted CLP in the first place," she said.
"We're good financial managers.
"Labor isn't, Labor wasn't, they never have been and they never will be."