The race to replace John Key is on, with three National MPs confirming they'll be running for the top job.

At this stage they are Finance Minister Bill English, Health Minister Jonathan Coleman, and Police Minister Judith Collins.

Bill has received the outgoing prime minister's approval, but that hasn't stopped other candidates coming out of the woodwork.

The temptation to be leader is, of course, high: National sits comfortably in the polls, while Labour languishes.

Whoever is chosen to lead the National Party on December 12 could very well steer a fourth-term government after the 2017 election.

As Judith points out in our interview with her below, choosing a new party leader doesn't happen often. Getting a shot at being Prime Minister is even rarer – John Key has seen off four Labour leaders during his tenure in the top job, for example, forever ending their ambitions.

Next year could be the only chance for these National MPs to get close to the shiniest baubles of office in the Beehive. SunLive interviewed Judith Collins to see what her reasons for running were, and found out her thoughts on Simon Bridges and working with NZ First.

Bill English and Jonathan Coleman have already thrown their hats into the ring. What do you think you can do differently to them?

Well, I believe this is all about the 2017 election. I believe it's going to be an extremely hard-fought campaign. We'll be asking the country to give us a fourth term, with a new leader, and it's going to be extremely tough.

I'm someone who can make decisions. I can make tough decisions; I can think on my feet. I make hard calls all the time and I believe it's really important for us to connect with all New Zealanders, whether they're women or men, or any ethnicity. I believe I can do that.

John Key has been a very successful Prime Minister. Much of National's popularity can be attributed to his personal appeal. Do you believe you can retain that popularity?

I think the main thing for me and the team, if I am successful, is to keep the party's high rating in the polls. But I know there can be a difference between the polls and how people vote. I think the last six or seven weeks of the 2017 campaign will be the toughest we've ever seen.

I do know this: I am a very tough person. I've been hardened by an awful lot over the years. I know I can endure that, and I believe I could deliver us a victory and work with other parties.

What are some of the issues you would campaign on more strongly than, say, Bill English?

One of the things I think is really important is to listen to people. One of the strengths I believe I have is being seen as authentic. When I say I believe something needs to happen, I really do mean it. When I say, for instance, our Resource Management Act reforms need to be more attuned to what people want in New Zealand, I absolutely believe it. That is one of the areas I would like to campaign on. I would also like to campaign on transport, and on law and order. But in particular, the RMA is an example of an area we haven't done as well in, and would have done better in if we could work with other parties.

And what other parties would you be happy working with?

It's always up to the people, isn't it? I was a lawyer and businessperson for 20 years before I came into politics; I'm not a career politician. My view is you have to do the deals you have to do in order to get the best outcomes. But I do know it is highly likely we will have to look further afield in addition to the current parties we have in government.

Such as New Zealand First, potentially?

Yes.

What about caucus support? Do you feel you have a substantial support base there?

I think caucus knows I am an absolute straight shooter, and when I put my hand up it is because I believe very firmly I can make a positive difference to the outcome next year. But it will be up to caucus. I'm not demanding people vote for me, or else something might happen to them. I'm simply saying to people I'm in the race, and I appreciate your support. I will be giving it my best shot, though, and we'll see how it goes.

What about deputy choice? Labour tends to run an American-style primary leadership contest, where prospective leaders sometimes pick a ‘running mate'. The National party has a different selection method, but do you have anyone in mind you would like to see as your deputy?

I think in the National Party the deputy is chosen very much the same way as the leader, by caucus. So we don't have the primary style of the Labour Party. I guess they've had a lot more practice at leadership battles than we have, but we prefer not to follow that method. If I were to be successful, I would of course accept the caucus view on who should be deputy. Caucus doesn't very often get the chance to change leader. This is one chance in ten years, and I believe it is disrespectful to tell caucus who should be deputy, if you are chosen as leader.

What's your relationship like with Simon Bridges?

I think my relationship with Simon is very good. We've worked together on a number of matters over the years, and I've certainly been a visitor to his fundraisers.

So in a Judith Collins-led government, he wouldn't have to worry about getting pushed to the backbenches?

I think he's a very capable MP and he has a tremendous future in front of him.

Assuming Monday doesn't go your way, and Bill English ends up being prime minister, would you support him 100 per cent?

My view is very firm: whoever is leader and deputy leader I will support them 100 per cent. I've always done that in my time in the National Party, and I would continue to do so. But I want to make it very clear that's what MPs should do.

All the way up to the 2017 election?

Absolutely, you have to do it. That's just the way it is.