Television New Zealand has admitted it made a mistake in using Bill English in a TVNZ 7 promo for a series on the economy.

The 45-second advertisment ran more than 30 times from October 18 to promote a new series called Focus on the Economy.

The broadcaster admitted its mistake while being grilled by Parliament's Finance and Expenditure Select Committee on the use of a shareholding minister in the advertisements.

TVNZ chief executive Rick Ellis told the committee today the channel produces about 60 to 70 promos a week, which fall under creative services and were not his direct responsibility.

"The promos are not part of the news and current affairs editorial process. That's marketing responsibility. So we might slip from time to time ... in the editorial sense. We learn from that and we move on," he said.

"I have the responsibility to ensure that the editorial policies and practices that have developed over the years at TVNZ properly adhere to and are ministered. And where we make a mistake that they are properly reviewed."

Mr Ellis said at the end of the day it was a promo and in "hindsight ... we might have made a different judgement call ."

TVNZ corporate affairs chief Peter Parussini said the promos were meant to mirror TVNZ 7 content for the month of November, focusing on the recession and economy in "some sort of plain English, so ordinary Kiwis can understand."

"We probably shouldn't have done that particular advertisement.

"And the head of marketing and I have discussed how when we do the usual review of the campaign at the end of the month that we need to talk about processes, so that in future those campaigns are done appropriately," he said.

He said there will be talks with the head of marketing at the end of the month to ensure future campaigns are carried out appropriately.

Labour MPs David Cunliffe and Brendon Burns made a formal complaint to TVNZ chief executive Rick Ellis on the basis that it appeared to be a political advertisement and allowed Mr English to repeat lines from past political speeches.

They believed it breached the Code of Broadcasting Practice as it failed to present any significant alternative points of view.

TVNZ originally stood by its decision to run the advertisement.

"We're happy that it's not in breach of the Broadcasting Standards Authority in terms of fairness and balance," spokeswoman Megan Richards said last month.

The promo began airing on October 18 and was taken off-air three weeks before it was due to end.