National Party MPs meet tomorrow to vote for a new leader to replace Bill English. Judith Collins is making a tilt at the job and says she's effective in opposition.
The other contenders vying for the leadership role are Steven Joyce, Simon Bridges, Amy Adams and Mark Mitchell.
Out of the five contenders only Ms Collins accepted our invitation to come on air this morning. She believed it was necessary to take every media request and that she saw it as an audition for the job.
"We can't just pick and choose in these opportunities, you do what you have to," she told Morning Report.
She's the only contender to have been in opposition before and was first to throw her hat in the ring for the leadership role.
"There is no entitlement to be in government. We have to hold this government to account," she said.
Ms Collins said the job will be a difficult one.
"Whoever is chosen will have a tough time, me or anyone else. Leader of the opposition is the toughest job in Parliament," she said.
She criticised what she saw as a move to the left in the National Party, particularly in health and safety legislation which she said hurt small businesses without leading to better outcomes for workers.
On the allegations of sexual misconduct coming to light, Ms Collins who spent 20 years as a lawyer, said they are part of a culture of entitlement in larger firms.
She said that in her early career she had to be very blunt and stand up for herself in certain situations. She preferred working in smaller firms but said some of the larger ones had made huge efforts in stamping out bad behaviour.
Mr English's resignation takes effect on 27 February.