Television New Zealand has requested more information from the Labour Party about its concerns over presenter Mike Hosking moderating the channel's televised leaders' debates before the general election.
Labour says it is worried about the political neutrality of Mr Hosking, who urged a business meeting last year to vote National.
Leader David Cunliffe said on Thursday that the matter was raised by his advisers.
"My staff have, I think, raised very legitimate concerns. The request for further information has come from Television New Zealand. My staff are responding to that request and we'll see where that goes from there."
Prime Minister John Key said while he has a personal view about interviewers, he will be turning up to all of the television election debates and doesn't think Mr Hosking is politically biased.
"The view I've always taken is there's lots of journalists that have a particular view. (TV3's) John Campbell was in the newspaper I think many year's ago saying that he was an Alliance voter.
"It doesn't stop me turning up and going on Campbell Live or going on numerous debates in the past hosted by John."
Meanwhile, Mr Key says he had no idea how his image was going to be used on the cover of a sports magazine.
Labour has raised questions about the Rugby News running a doctored photo of Mr Key with four All Blacks as the cover of its latest issue.
Mr Key said his office was asked whether he would pose for a photo for the magazine, and he did.
"I've been on Woman's Weekly to John Rowan writing a book. The reality is that lots of people choose to use my image or ask me to pose for things - sometimes it's positive and sometimes it's negative. I don't make those calls."