Prime Minister John Key says he believes Christine Rankin can do a credible job with the Families Commission, but she will have to stay focused on her role.
The appointment has caused an uproar and reports yesterday that Ms Rankin was instrumental in a marriage break-up have fuelled the controversy.
"As far as I'm concerned she's been appointed a commissioner, one of seven in a part-time job, to advocate for families and particularly because of her expertise when it comes to abused children," Mr Key said today.
"That's what I want to hear her talking about and nothing else."
Sunday newspapers reported Ms Rankin was involved in the break-up of the marriage between Wellington real estate agent Margo McAuley and Kim MacIntyre.
Ms McAuley was found dead in October last year.
Her death has been referred to the coroner. Ms Rankin and Mr MacIntyre were married in January this year.
Ms Rankin told TVNZ's Sunday programme she was not having an affair with Mr MacIntyre at the time of Ms McAuley's death.
Mr Key said the Government's general rule was to keep separate the personal and professional lives of people it appointed.
"If you accept the argument that her main area of expertise is in abused children, then I don't think you could point to anything in her background that would indicate she's not qualified to talk about that issue," he said at his post-cabinet press conference.
Ms Rankin said on the Sunday programme Ms McAuley had been a long time friend, who was complex and at times difficult.
"Many think that there was an affair. There was not. We did get married at the beginning of this year and that may seem unusual to outside eyes," she said.
"But sometimes when things happen that are almost impossible to deal with, in each other you find the strength and a way to live."
United Future leader and Revenue Minister Peter Dunne, who created the Families Commission under an agreement with the previous government, wants Ms Rankin to step down.
He said today she had too much baggage to be effective and would be a divisive and disruptive influence on the commission.
- NZPA
