National fell below Labour in yesterday's Newshub Reid Research poll, which had National on 41.6% and Labour on 47.5%.
In the preferred Prime Minister stakes, Labour leader Jacinda Ardern was on 41.8% while Bridges was on 5%. Collins was ahead of Bridges on 6.2%.
This morning Collins, who unsuccessfully ran for the party leadership when Bill English stepped down last year, said Opposition leader was the toughest job in politics and a role she was "not even interested" in.
"The person I'm most pleased with beating is Winston Peters," she told reporters.
"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."
Asked whether caucus colleagues had spoken to her about running for the leadership again, she said she did not disclose the substance of private discussions.
"People talk to me all the time about lots of things."
Beating Labour was not about who could match Ardern, but which party had the better team, she said.
"It's not a one-on-one thing ... if we put our team versus their team, we're doing very well.
"Simon and I work very well together. We all need to stay focused on the end-game here, and the end-game is a better government for New Zealand."
Bridges said he had no concerns about Collins polling higher than him, or about whether she had caucus support for a leadership challenge.
"We've got a caucus that's strong, that's united, and that has 55 leaders ... I'm very confident and comfortable in my leadership."
He said some his low polling was due to having to deal with the explosive fallout with former National MP Jami-Lee Ross.
Ross returned to Parliament today, and Bridges said he did not intend on paying any attention to him.
"We've moved on."
If they met in the corridor, Bridges said he would say "hello ... not a lot else".
Ross laid a police complaint last year about a donation to the National Party that he alleged was fraudulently handled, and Bridges revealed that he had recently provided a written statement to police.
Bridges repeated that he did not think the party had done anything wrong.
"I'm incredibly confident about that. As I said at the time, it's a baseless, scurrilous accusation."
Rodney MP Mark Mitchell, who also ran unsuccessfully for the leadership last year, said Bridges was doing a great job and the preferred PM poll result was not worthy of attention.
"He's shown a lot of resilience. He had some big challenges to deal with last year. I think he dealt with those very well."
He said Bridges had the full support of the caucus and expected his preferred PM stakes to improve.
Senior National MP Gerry Brownlee said there was no chatter about the leadership.
"We're quite happy at the moment. Everything's going along very well for us."
