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This morning Bridges confirmed he was facing a leadership challenge but was "very confident" he would win it.
- 'Paula Benefit': Bridges' embarrassing on-air gaffe
- Power play: Simon Bridges appears to call challengers' bluff
- Bridges and Bennett leadership challengers named
He did not name the challengers, but it is clear he was referring to MPs Todd Muller and Nikki Kaye.
Collins and her fellow MP Mark Mitchell have both since said they would not be challenging Bridges for the role – although it remains possible one or both would contest it if it came up.
Muller and Kaye are yet to respond to approaches for comment
That was triggered by a Newshub-Reid Research poll which had National at just 30.6%, and Bridges' ongoing struggle to get any traction as preferred Prime Minister against Prime Minister Jacinda Ardern.
Collins told the Herald this morning that she did not believe a no-confidence vote against Bridges would pass, and she had "no intention" of standing in a leadership contest.
"It is very important I think that there is as much caucus unity as possible going into any election and I'm just not interested in being part of anything other than doing my job," she said.
"My view is I am just focused on the job and I am not part of anything that is going on. I am keeping myself well out of everything."
Collins contested the leadership in 2018 against Bridges, Steven Joyce, Amy Adams and Mitchell when Bill English stepped down.
Mitchell has also ruled out challenging Bridges.
Mitchell would not comment on whether Muller and Kaye were the challengers: "I'm sure that will become clear on Tuesday."
Mitchell said the resolution of the challenge would be "done quickly".
He knew who the challengers were - "conversations had taken place" - but nobody had called him to ask for support.