The bitter dispute has been going on for months, but most have been until now unwilling to speak, fearful it would bolster their enemies, including mining companies, Gunns and Aboriginal leaders critical of the society's conservation stance in Cape York.

''We don't want to lose members over this and we don't want to lose support, but we can't have this huge internal rift continue,'' said one senior campaigner.

The Sunday Age has learned the problem came to a head in July last year, when the society's national campaign committee, a powerful body of senior campaigners, passed a 9-2 vote of no-confidence in Mr Marr over his interference in the appointment of a senior campaigner.

The campaigners regarded it as the last straw in a long list of grievances about Mr Marr's autocratic style. Almost all state-based campaign centres, except for South Australia, have now turned against Mr Marr.

In retaliation, Mr Marr held an annual general meeting in November known only to a small group of people. Under the organisation's constitution, the notice of the meeting must be advertised in a Tasmanian newspaper. It was advertised not in the Hobart Mercury or Launceston's Examiner, but The Advocate, the Fairfax Media-owned newspaper published in Burnie, which has the lowest circulation of the state's three dailies.

At the meeting, a board favourable to Mr Marr was elected and the constitution changed so that it now takes 4500 members to call a special general meeting, rather than the previous 20. Board member Peter Langoulant, who attended the November meeting but then resigned, told The Sunday Age that the constitutional change and secrecy around the meeting was designed to shore up Mr Marr's position.

''I don't believe it was right, even though I was a party to it,'' he said. ''It was a secret AGM … and I think it disenfranchised people. [The Wilderness Society] was supposed to be a democratic, consensus organisation and I think it has moved away from that,'' said Mr Langoulant, a finance manager from Victoria.

Mr Marr and board convener Lyn Goldsworthy declined to be interviewed, but board member and spokeswoman Lena Aahlby said the November meeting was legally held according to the constitution. She declined to explain the reason to advertise only in The Advocate. But in a December 22 email, Mr Marr announced to staff that the annual general meeting happened two months previously to ''protect staff and volunteers'' from an ''attempt to destabilise or remove TWS Inc senior management''.

Three former board members, who declined to be named, have also expressed concern about the lack of financial transparency and accountability. This is coupled with a growing disquiet among campaigners about how donations are spent, particularly on consultants.

A former board member said that bad behaviour could be found on both sides of the rift, but there was ''some justification'' for allegations that management were bullying staff. ''You are talking about a general intimidation: if you disagree with me, I'll try and bully you or beat you into submission,'' said the ex-board member, who is not on staff.

Ms Aahlby said she ''did not think'' there was a culture of bullying at The Wilderness Society. When asked if Alec Marr bullied people she said: ''I can't answer that. I hope not.'' She attributed the society's internal tension and accountability issues to its passionate staff and fast growth - a door-to-door campaign saw membership spike dramatically this decade and donations grow from around $1.2 million in 1996 to $15 million last financial year.

''We are taking the crisis seriously, the unrest seriously, but we are responding in a way that will put the Wilderness Society on a good footing for the next decade or so,'' Ms Aahlby said.

Despite staff concerns, a performance review last October found Mr Marr was performing to the board's satisfaction, she said.

The split comes as the Tasmanian Industrial Relations Commission last week found the Wilderness Society had unfairly sacked its database manager David Wanless. In his judgment, Commissioner Tim Abey said evidence in the case pointed ''overwhelmingly to an organisation which is beset by dissent and discord, and that Mr Wanless was, and it would seem, still is, far from alone in expressing these concerns''. It is believed the society's management will appeal against the decision.

Former society board member Geoff Lambert, another Franklin River veteran, said the feud reminded him of George Orwell's Animal Farm, the allegorical story about a farm-animal revolution that goes wrong. Mr Lambert described the sacking of Mr Wanless, a dedicated and hard-working employee, as the equivalent to when Boxer the horse was sent to the knacker's yard to be slaughtered.

''I think this is a sad thing. I nearly cried when I heard about this dispute,'' said Dr Lambert, who has known Mr Marr for 20 years. ''I think it is just human nature - the same people that are the subject of disquiet now would have looked upon this (behaviour) with the same disquiet 10 years ago. I don't think you can put it down to them being bad people, I think they have just gone astray.''

The Sunday Age can also reveal that:

■ Despite winning a large settlement from the Tasmanian forestry company Gunns, the four-year court case against the Wilderness Society has had a chilling effect, according to senior campaigners, making the organisation shy of engaging in direct protest action.

■ A 2008 organisational audit by consultants Dattner Grant highlighted ''a combative approach by managers'' and stories of a ''lack of transparency around pay structures, including commissions and bonuses, as well as perceived perks''.

■ For the first time in its history, the Wilderness Society has become heavily unionised, amid a ''pervading sense of fear about job security'', according to one internal document.

■ The society is suffering high staff turnover, with almost 60 per cent of 94 TWS Inc staff leaving the organisation in the 13 months to September 2009, according to an internal document.

The rift is also characterised by a generational divide. Younger campaigners complain that the veterans of the Franklin River campaign missed the boat on climate change and that, in the wake of the Gunns case, the organisation no longer takes risks.

They say Mr Marr has no national presence and is rarely found lobbying for the environment in Parliament House. ''In state campaign centres, a new breed of activist leaders is emerging, people who are responsive, technologically savvy, innovative … and with the energy to reach a broader demographic,'' one senior campaigner said.

Another campaigner said the whole environment game had changed because the majority of under 40s understood the need for sustainability. It was no longer good enough, the campaigner said, for activists to act as the vanguard.

''I am not convinced the environment movement is ahead of community views,'' the campaigner said. ''I think we may be part of problem. I think we need to get off our arses and talk to Australians about the problem.''