"I just think it's an indication that people can see that I have been working on the KiwiBuild issue and they can see too that I'm holding the Government to account – I think that's what we're all doing," she said, when asked about the preferred Prime Minister ranking.
But she remained upbeat about National's overall support.
Last night's poll had the party on 42 per cent – down 4 per cent on the previous poll.
Asked at what point National would start to get nervous about its level of support, Collins said: "I don't think you get nervous when you're in your 40s when it comes to polling."
"I think that 42 per cent is a great result."
Last week, after the Newshub/Reid Research poll, Collins said she was "not even interested" in the job of leader of the National Party.
"Opposition leader is the toughest job in politics. It's a very tough job ... I'm a lovely, sweet person, not given to that sort of toughness at all. I'm just sometimes resolute."
Meanwhile, Bridges was singing a similar tune.
"You find me another political party anywhere in the world halfway through the first term of a new Government that's consistently in the 40s – you won't be able to."
He said there is a lot that will happen before the election.
"I know I'm the best person to lead the National Party."
He said a capital gains tax, which is likely to be recommended by the Tax Working Group later this week, would help bolster National's support in the polls.