National MP Denise Lee who slammed Judith Collins in leaked email speaks out in support of her

National MP Denise Lee has spoken out in support of leader Judith Collins after slamming her in an email leaked to Newshub during the election campaign. 

Collins announced on Sunday that a review would be undertaken into National's campaign and its performance as Opposition over the last three years, after it lost 12 MPs on Saturday - not including the 13 who had already retired or stepped down. 

Collins also revealed that National's internal polling showed its support dropped by 5 percent after Newshub was leaked an email by Lee showing her being critical of the leader's intention to review Auckland Council without consulting her first as spokesperson. 

Lee described the idea in an email as a "highly problematic idea" to her caucus colleagues. She also panned it as "another working group" and said it would be "a nightmare". 

Collins led National's first caucus meeting since the election at Parliament on Tuesday after which she held a press conference flanked by the shrunken down caucus - including Lee who kept her Maungakiekie seat - following their crushing election defeat.

Lee was asked during the press conference if she would comment on the leaked email and Collins told her she only had to speak to the press if she wanted to. 

"Are you there Denise? Do you want to come forward? You don't have to - whatever you choose to do," Collins said. "We don't want Denise being bullied by you," she said to the media. 

"Good girl," Collins told Lee as she joined her at the podium. 

Lee, when asked if she had any comment on the email she sent during the campaign, said: "No, I definitely don't. We are, as Judith has said, going through an internal review and all my comments - as they have been the whole time - will be reserved for closed doors."

Asked if she regretted sending the email, Lee said: "All my comments will be reserved for our internal process. I support Judith as the leader. No more comments, thanks."

National's finance spokesperson Paul Goldsmith was asked how much responsibility he has taken for National's defeat, after a $4 billion fiscal hole was discovered, along with other issues, in the party's fiscal and economic plan. 

"Oh look, we all take responsibility for our actions, myself included. It's up to the leader who she wants to appoint in that role," Goldsmith said. 

"I think that's enough of that," Collins told reporters. 

"Decisions around portfolios will be made once we have the MPs confirmed, because we obviously have the special votes, and also after the Government puts in place their portfolios because we're going to match the right people," she said. 

"Everybody is going to let me know what their views are and what they want and I'm going to do my very best to do the best I can."

National MP Simon Bridges - who was rolled as leader in May by Todd Muller - was asked if he could have done a better job during the campaign. 

"I think that's a silly question. We are where we are right now. I support Judith 100 percent as leader of the National Party and I'm going to continue doing that right the way through this term," he said. 

Collins dismissed questions on whether MPs who organised the coup against Bridges should take responsibility for the party's defeat. 

"Do you know what? I just think everyone's moved on, everyone's very focussed on the fact that we have a review coming up. We will be obviously able to share our views and I think it's really important that we're not focussed on that," she said. 

"I think it's really important the most damaging thing we're seeing is the fact that there's no economic plan from the Government. We're focussed on doing our job in Opposition and as part of that in building a very tight Opposition that's focussed on our roll.

"We're not going to be navel-gazing in the media."