Corrections and Police Minister Judith Collins is refusing to rule out a bid to replace John Key as Prime Minister and leader of the National Party.
Ms Collins told Newshub she was yet to make up her mind about challenging for the top job.
"I haven't made my mind up. I'm thinking about it. I'm not really prepared to go any further," she said.
In a telephone interview, where she was asked repeatedly about a leadership bid, Ms Collins refused over and over to rule out a leadership bid.
She said she would make up her mind after tomorrow's Caucus meeting when she knows what the process will be.
Mr Key has endorsed Bill English as his successor but Mr English has not yet officially put his hand up.
While Mr Key has publicly backed Bill English to take his place, he says he'll be 100 percent behind whoever gets the job - including if it goes to Ms Collins.
"If there's a contest [for deputy or leader], in itself that's no bad thing... As long as the party does the right thing, has a contest and then unifies behind the new leader and the new deputy leader... then we should all be comfortable with that."