A political scientist believes the Government will be feeling the heat as the New Zealand First Party faces allegations surrounding its donation practices.
The Serious Fraud Office is weighing up whether to probe the accusations that the party is hiding donations in a slush fund.
Prime Minister Jacinda Ardern, meanwhile, has demanded a full independent look at political donation laws.
Political scientist Bryce Edwards told The AM Show Ardern is correct to conduct some sort of inquiry.
"I think it's likely to sink New Zealand First in 2020 and it will dog this Government throughout this year," he said.
"It goes to the heart of democracy and the way it affects people's lives.
"We're supposed to be the most corrupt-free country on the planet yet what we're seeing here are just major issues."
Edwards believes Ardern will be weighing up all her options including an early election.
"Yes, she's already said September 19 is the date that she wants to go," he said. "I think she will look at an earlier possibility if the Serious Fraud Office decide to investigate.
"Whatever happens, we really want a quick investigation that gives voters certainty."
New Zealand First leader Winston Peters has denied any wrongdoing and described the claims raised in November as "filthy allegations without any proof".
But the Electoral Act is very clear, according to ACT Leader David Seymour.
"Our laws say that the public do have a right to know who is giving significant donations to political parties," he told The AM Show on Tuesday.
"The law, at the moment, says 'significant' is one person giving more than $15,000."
Peters said in a statement on Monday that New Zealand First welcomes the Electoral Commission's referral to the police, saying it "confirms our prior view that only the police would have the powers to determine the issues involved".
Political commentator Grant Duncan said on the back of Sunday's Newshub-Reid Research Poll, the party will be worried.
The poll revealed New Zealand First had slipped by 0.4 percent to 3.6 percent.
Duncan told Newshub the allegations will leave a bitter taste in the mouths of those faithful to the party.
"New Zealand First supporters are often quite conservative and they look to Winston Peters as a man who is prepared to hold people to account."
Duncan said it's terrible timing for the party, adding it could even push some voters towards National or Act.
"There is a danger that, even if they aren't necessarily proven in court, they do undermine the confidence of New Zealand First supporters."
In his statement on Monday, Peters added, "In light of the Electoral Commission's findings today the New Zealand First Party can also confirm it will be reviewing its arrangements for party donations.
"This party is built on the support of loyal supporters and donors and believes it has followed the law implicitly."