The Queensland Nurses Union will disaffiliate from the Australian Labor Party’s Queensland branch, stripping 12 votes from Anna Bligh’s Left power base on the state conference floor and increasing pressure on Australian Workers Union kingpin Bill Ludwig to knife her as premier.

The decision to withdraw the union’s $80,000 annual donation was reached by the Nurses’ governing council earlier this year and communicated to delegates in July — but is yet to be announced publicly. The move will shift support from the party’s Left and into the hands of right-wing powerbrokers and could calm dissent over the government’s controversial $15 billion privatisation program.

Despite arguing against privatisation in principle, the QNU, which has about 35,000 members, has been a key backer of Bligh and resisted a push (alongside Julie Bignell from the ASU Clerks) from other Left unions to force a special conference in February that would have seen the premier scuttled. The petition spruiked by Electrical Trades Union state secretary Peter Simpson fell just short, with the Nurses’ abstention crucial.

But while the Nurses were a key roadblock to a Bligh knifing, their delegate spots will be partly subsumed by the Right, who have until now notionally backed the premier. In an echo of Kevin Rudd’s assassination, this means it “will be Bill Ludwig, and Bill Ludwig alone” that will determine her fate, according to one senior union source.

QNU state secretary Gay Hawksworth told Crikey her members have been unhappy over a Queensland Health payroll bungle earlier this year, with many questioning the wisdom of shunting tens of thousands of dollars each year to a party that wasn’t able to pay them properly. But Hawksworth said the decision to disaffiliate beginning in March next year had been taken earlier, and added that until then the union was still inside the tent.

“This is more about a different way of doing politics … party politics isn’t necessarily accepted by the younger generation,” Hawksworth said.

In recent months, Bligh has continued to flatline in the polls, with her approval rating sitting at an embarrassing 26%, according to the latest Newspoll.

Before the defection, the Left controlled about 49% of the votes on the state conference floor and were six votes off commanding a majority. But with the Nurses decision, while one roadblock to an anti-Bligh putsch has technically been removed, it has been replaced by another in the form of an expanded Right. Once considered a key trigger for a spill, the controversial privatisation plan, backed by AWU operatives in caucus, is now almost certain to proceed.

Yesterday, Queensland Treasurer and perennial leadership hopeful Andrew Fraser (from the Old Guard) and Queensland Rail chief Lance Hockridge announced the controversial privatisation would proceed with an IPO in November — Australia’s biggest since the last Telstra offering.

Labor theorists north of the Tweed suggest Bligh could go quietly before the 2012 poll on the understanding that Fraser would assume the state’s premiership. Fellow ‘Premier’s Faction’ player Cameron Dick, and supporter Paul Lucas, are believed to be wavering over fears the party would be wrecked at the ballot box on the youthful Dick’s watch.

There are suggestions the QNU defection could lead to further fissures in the Left, with some Bligh loyalists believed to be sniffing the leadership breeze in league with the right.

“The factions are starting to come together and people like [assistant state secretary] Jackie Trad are being excluded because they’re thought of as being too close to Anna,” one Left powerbroker told Crikey. Key Bligh henchwomen including Left convener Wendy Turner is believed to have pulled her support and is now “rolling with the AMWU”, the source said.

However, a suitable replacement remains elusive, despite the member for Brisbane Central, Grace Grace — who has managed to skirt most of the stench surrounding the privatisation debacle — emerging as a chief agitator inside caucus. The popular ex-unionist is believed to command significant backbench support, although there are also fears she could surrender her inner-city seat to the Greens, rendering the wisdom of a pro-Grace push problematic.

• Meanwhile, in other Queensland union news, the QPSU and LHMU have called off their merger that would have created a super union of 70,000 under the control of ambitious QPSU state secretary Alex Scott.