New Zealand First MPs say they are fully behind the party leader Winston Peters despite the continuing controversy over donations.
ACT leader Rodney Hide has laid a complaint with police over New Zealand First's return of donations for 2007.
Mr Hide alleges that New Zealand First's nil-return is false, after the Spencer Trust confirmed it made a payment to the political party last year in excess of $10,000.
A Serious Fraud Office investigation and a Privileges Committee hearing over other donations are already underway.
However New Zealand First deputy leader, Peter Brown, says the party is in good heart.
New Zealand First MP Ron Mark says he is encouraged by supportive emails and phone calls from members of the public.
In the latest Roy Morgan opinion poll New Zealand First support dropped from 6.5% to 2.5%. The poll of 841 people was conducted between 18 August and 31 August.