The Greens are embroiled in an ugly spat in the southern seat of Davenport ahead of a high-profile by-election later this month.

Two-time Greens candidate and local Occupational Health and Safety consultant Stephen Thomas has quit the party – taking his campaign team with him – citing a broader split between “fundamentalists and moderates”. He has since been running as an independent, until yesterday, when he withdrew to concentrate on a tilt at federal parliament.

But party insiders argue Thomas is merely disgruntled at missing out on preselection. He previously ran for the Greens in Boothby in the 2013 federal election and Davenport in last year’s state election, when he garnered 15.3 per cent of the primary vote.

“I achieved an increase in the vote (of 1.6 per cent) for the Greens at the state election,” Thomas told InDaily.

“I’m a local, I live in Davenport; I’ve lived in Davenport since 1982 … I had a reasonable expectation I’d be preselected again for the Davenport by-election (but) I was overridden.”

A postal ballot of all state Greens members, to which around a third responded, saw Thomas lose to former Waite campaign manager Jody Moate, 117 votes to 84.

“In my mind, that’s a significant split in the Greens – the party’s polarised between the fundamentalists and the moderates,” Thomas said.

“I put myself forward as a moderate, willing to negotiate and be pragmatic; I would even consider working in a coalition with the Labor Party (as) there’s no way the Greens are going to win (Government) in their own right.”

Thomas says the “art of politics” is about “being pragmatic and getting good outcomes for the people you represent”, and he is a firm believer the Greens should be in a coalition with Labor.

“If the Greens continue along the path of protesting and are seen to be a party of protest and not a party of putting forward legitimate alternatives to problems that arise, they’re never going to be in a position of power or influence,” he said.

“Some would argue I’m trying to run a smear campaign against the Greens, or just being spiteful … but the preselection outcome was for somebody who was both a really hardcore fundamentalist Green and a candidate who does not live in the area.

“My own belief is preselected candidates should wherever possible have a connection to the area they represent.”

Moate, however, says she lives “literally five minutes away” from the electorate, recently vacated by retiring Liberal Iain Evans, who held it with an 8.1 per cent margin.

“I’m not going to let a line on a map stop me representing the people of Davenport,” she said.

She is diplomatic about the fracas, explaining: “We had a statewide ballot that all members were able to vote in; I won the ballot. That’s pretty much the story.”

Asked whether Thomas’s reaction to the result was “sour grapes”, she said “different people react differently to winning and losing”.

“He’d really have loved to have won and that’s fine (but) I wouldn’t use the term sour grapes … He’s obviously disappointed.”

The disappointment was evidently contagious. Thomas’s erstwhile campaign manager Jacob Hodgman and another supporter, Corina Kuoni, similarly quit the party in protest.

“Corina and I had already decided to leave the party, because of an unprofessional attitude and the fact they couldn’t get anything done,” Hodgman said.

“It’s like a mothers’ meeting – nothing gets done.”

Thomas puts it differently: “It turned out I had significant issues with internal Greens party processes … the party in SA is quite polarised between fundamentalists and moderates and the leadership will not recognise that.”

The spat got even uglier, with social media taunts thrown, and legal threats after candidate photographs taken by Kuoni for last year’s state poll were used by the party to promote its candidates in the recent council elections.

Thomas’s campaign Facebook page before he abandoned his tilt at Davenport.

State MLC Tammy Franks admits the experience has been “difficult” for the party, but says any serious political party has to “choose the best candidate to put forward”.

“We had to make a hard choice, but I think it was the right choice,” she said.

But she railed against Thomas and Hodgman’s analysis of the party’s culture, which she calls “absolute rubbish in terms of their understanding of the party”, an understanding “rooted in their own self-interest”.

Moate too, say’s the scathing critique is “not my experience in the party”.

“I’ve had a really, really positive experience since I joined (in 2012); there’s a broad range of Greens but I feel we’re quite unified,” she said.

“As any party, you have differing opinions (but) I’ve always felt we’ve been able to talk them out.”

Countering her critics’ claims that she “knows nothing” about the local area, Moate cites bushfire risk management and public transport as key issues affecting the electorate.

Thomas, though, having established a “Stephen Thomas, Independent for Davenport” Facebook page and actively campaigning for the seat, withdrew his candidacy this week, citing the “daunting logistics”.

He’ll make his second tilt for Boothby at the next federal poll, this time as an independent.

“I’m not all that wedded to state politics,” he admits.

“I’ve got a personal view we’ve got one too many tiers of government.”

The Greens will formally launch their campaign at a function tonight.