Act Party voters "came home" this election but now leader David Seymour has the challenge of keeping them there, says its former deputy leader Heather Roy.
Last night the party was awarded its best ever result of 8 per cent
giving Act 10 MPs in Parliament after almost a decade of Seymour being its sole representation.
Roy, who was an MP from 2002 until 2011, said the result wasn't a surprise as reflected in the recent polling.
"David Seymour will be delighted to have friends with him in Parliament.
"I think he probably wouldn't have anticipated having quite that many but a caucus of 10 actually shows that he's made some real gains in the time that he's been in Parliament on his own."
Roy said the "million dollar question" was how Seymour and Act could hold on to its support and momentum through the next term.
Seymour earned the support through his "steady and strong" philosophical base that he'd engaged with over the last two terms and had benefited from National weakening and the backing of the Council of Licenced Firearms Owners (Colfo).
"It's really tempting in the small parties to try and cover everything but he resisted that temptation and it was absolutely the right thing to do, in my view.
"He picked his issues really carefully, was absolutely on point for Act's philosophy and I think he's been rewarded for that.
"The core Act vote has come home, David Seymour's challenge now is getting it to stay home."
This term the new Act MPs were going to have to perform really well and be very united as a caucus - and that would take discipline, said Roy.
Seymour would likely be drawing quite heavily on his deputy Brooke Van Velden who has Parliamentary experience as a staffer and Number 3 Nicole McKee who came from the Colfo lobby.
He would also need to find a really capable chief of staff to help him manage
growing his caucus from one to 10 and get them functioning quickly as a team.
"The key to success for them will be choosing the right issues and holding this Government to account. He's quite capable of doing that but they need to have a much bigger voice in doing that."
Act can "go further" when talking about the economy than the National Party feels comfortable doing, Roy said.
As well, the Covid-19 response, unemployment and housing would all be front and centre for the next Government which Act should have a key role in Opposition on.
"[Labour's] been elected because they've handled crises well. They've not been elected because they actually achieved anything transformational or progressive - they failed on all of those markers."
Former Act leader Don Brash, who led the party for seven months before resigning after a poor election result in 2011, said the party would need to continue raising important issues in Opposition given they had no ability to influence policy.
"My worry is that the Government has won a landslide victory without any specific policies to deal with the challenges which New Zealand has in front of it - and those are very significant challenges.
"There's no indication, for example, about how they're going to fix the housing affordability issue which is the biggest single cause of inequality in the New Zealand society."
The biggest challenge the new Act caucus faces is that only one of them - Seymour - has experience as an MP, he said.
As well as Van Velden and McKee, Seymour will bring with him Chris Baillie, who is a teacher and former police officer from Nelson, civil engineer Simon Court from West Auckland who worked at the Auckland Council before starting his own firm and Karen Chhour who is a self-employed mother of four from Auckland.