"I didn't challenge for the leadership."

That's the word from senior National MP Erica Stanford who says she "categorically" supports the prime minister following a tumultuous leadership bid last week.

National Leader and Prime Minister Christopher Luxon survived a confidence vote in his leadership last week - his second in four months.

Stanford held an impromptu press conference at Wellington Airport on Sunday, her first media appearance since the leadership spill.

Last week, Stanford - rumoured as a possible contender for the party leadership - did not immediately say if she had confidence in Luxon when asked by reporters last week at Auckland and Wellington airports but said in a statement later in the week that Luxon had her full support and the caucus was unified behind him.

Fielding questions from media, Stanford ruled out ever plotting against Luxon, who she said was a "wonderful leader".

"I've told you a million times, I support him wholeheartedly."

Stanford admitted she "maybe" should have stopped to answer questions from media when walking through the airport "but here we are".

"It was nothing to do with not supporting the prime minister, it was just not answering your questions because I'd answered them over and over again all week, and you keep printing the opposite.

"I thought, you know what? I'll take a different tack." she said.

Asked if she would put herself forward as National leader should the party lose the election, Stanford said she had already ruled herself out.

"I want to be the Minister of Education and Immigration - mostly Education - for the next nine years. I love my job, and I've got so much more to do." she said.

Stanford also denied she was the "numbers guy" for Chris Penk, who lost his portfolios in the aftermath of the confidence vote.

"I didn't do any numbers at all. I can categorically tell you, I don't know if anyone did do any numbers. I certainly didn't. I don't know what the numbers were."