From lawyer to unionist to MP to an employer's role with the Super City, Laila Harre has covered all the bases.

She calls it a flirtation. I glibly try "dalliance". For former Alliance torchbearer Laila Harre, the prospect of succeeding Te Atatu MP Chris Carter in Parliament - and returning to the Labour fold she abandoned in the 1980s - is indeed tantalising. In the change management-speak she sometimes uses these days, it really would close the circle.

Small problem (quite apart from whether Labour would have her back): she already has a job to go to. She leaves next month for a two-year stint based in Fiji with the International Labour Organisation, ending what some of her critics portray as an employer's role with the agency setting up the single Auckland council.

She's always had her opponents on the right but her move last year from the National Distribution Union to the Auckland Transition Agency had lefties sharpening their knives - and if there's one thing unionists like more than slagging off the bosses it's slagging off each other.

Politer critics compare Harre's career trajectory to that of a butterfly. Some diehard lefties use a far baser word to sum up her path from lawyer to unionist to MP to unionist to "boss' lackey". Which would be interesting if it were true. But it's not and those who think she'll be flitting about the Pacific Islands while workers here struggle with the National Government's employment changes should think again. More likely, she'll be boring the bosses into submission with her ceaseless, even-tempered arguments about valuing workers and the power of collective thinking.

As good mate Matt McCarten maintains: "She is very much a project-based person. Once she feels she's done her job she doesn't believe in sticking around."

Harre, 44, was handpicked by transition agency boss Mark Ford for the role as "human resources and change manager". He knew her from his time as chief executive at Watercare, when she was on the Auckland Regional Services Trust that appointed him. Her critics will no doubt say she's getting out before the real hurt is felt - by those who have no jobs in the new council, those who have to swallow big drops in pay and conditions and those forced to travel to the other side of town to keep a job. She points out she accepted the ILO post 18 months ago, then delayed as long as she could.

She strongly supports the single council for its regional approach to big city issues and its local boards which, she says, will be more democratic. "I think some who have criticised me for taking on this role would prefer the Super City didn't work.

"When Mark approached me, I saw an opportunity to practise what I preach as a unionist and that is to harness the benefits of worker participation, union protection, constructive engagements with management and implementation of change - and I think that's what we've been able to achieve."

Activist John Minto was among cynics who saw Harre's appointment as smart politics by the agency rather than a boost for the workers. But insiders say she has made a major contribution to the transition process - starting with a collaborative approach which influenced the new council's organisational structure and preserved jobs. She fiercely opposed some changes.

"There were some pretty voluble discussions between her and senior ATA people and she's a woman who holds her ground," says Waitakere Deputy Mayor Penny Hulse.

She won respect for her professionalism. She is highly principled and does show emotion but can see both sides, colleagues say.

Mayoral candidate Penny Bright is among the unplacated critics. "No way can someone who's helping the corporate takeover of Auckland consider themselves 'Left'. ... She's crossed the line."

Harre is impressed that staff have set aside their personal insecurity to help shape the new organisation. But there is pain to come for some of the 6800 caught up in the biggest restructuring the country has seen.

The Government is looking for efficiency gains and middle-management staff on individual contracts are the most vulnerable.

Even though the futures of many remain up in the air, the PSA is happy with the collective agreement signed this week for its 3000 members. "[Harre] wasn't at the bargaining table but she was a key person on the employer side in arranging the whole thing," says PSA secretary Richard Wagstaff. "And she knew how to engage with us effectively. Often that's lacking among employers."

Harre may have been in it for the workers, but the HR role is a diverting addition to her CV highpoints which include setting up New Labour, then the Alliance, the parliamentary win on parental leave, pay equity for public sector nurses (a deal which flowed on to the private sector) and unionising supermarket staff. She says the agency is not the employer but a facilitator of change.

She's a dab hand at restructuring after shaking up the Nurses Organisation and, more infamously, the National Distribution Union. In rolling veteran unionist Mike Jackson in 2004 to become general secretary, she displayed a steely side which Alliance supporters felt was lacking in 2002, when she might have toppled Jim Anderton.

The NDU was deeply split over Harre's coup. Jackson loyalist Karl Andersen was an early convert and is now a member of her Tuesday night pub quiz team. He says she brought formidable organisational skills and introduced strategic planning, helping the union to grow in the uncharted territory of low-paid retail workers and win a landmark victory at Pak 'n Save.

"She was a hard taskmaster," says Andersen, the union's assistant general secretary. "She set very high standards for herself and expected others to do the same. When you are driven like she is you can rub people up the wrong way. "I don't think she could be in a job where she couldn't influence decisions. She gets the bit between her teeth and she's a formidable opponent."

Which fits her political image - but in person she is far from staunch. Interviews make her deeply nervous; she is friendly but cagey and anxious to be portrayed in a good light.

She agreed to be interviewed, she says, because she has some messages for the Labour Party. She says "good signals" are coming that the party is re-examining its position and may shift back to its social-democratic roots. "I think it's really important they aren't just focused on winning the next election. They need to develop a programme first and take as long as it takes to to win support for that programme." She seems unconcerned that her "tantalising" flirtation may not be reciprocated by those in Labour with long memories.

"Parliament does feel a bit like unfinished business for me because of the way the Alliance ended and opportunities closed off to promote the kind of policies I believe in."

First steps first. The ILO brief seems tailor-made for her - capacity building among the unions; improving worker participation in decision-making; creating jobs. She went to primary school in Fiji while her anthropologist father worked there and has long hankered for a job in the region. The ILO appeals as a tripartite body with employers, governments and unions represented.

"Unlike some of my critics, I support a collaborative approach to industrial relations."

She and husband Barry Gribben, a health researcher, will celebrate 25 years together just before she leaves their Te Atatu Peninsula home with views across the harbour for the posting. Older son Sam is studying communications in Wellington, younger son Jack is still at school.

"I'm going with my backpack - we've still got to work out how we are going to function for that couple of years. Throughout our years together, Barry and I have just said 'yes' to things and then seen how it goes. We've never had much of a plan ..."

Which may surprise those critics.