Act leader Don Brash, arriving to a the predictable standing ovation, said New Zealand was a great country - "nobody gets shot" over political disagreements - but it was at risk, and most of its social problems was due to a stagnant economy.
The IMF predicted that the economies of 148 countries were going to grow faster than New Zealand's in the decade to 2016, he said.
"We would have been in a state of national mourning if even one other country had beaten us at rugby. We seem relaxed at being 149th in the economic growth stakes."
He outlined Act's policy priorities:
* Capping future Government spending to increase only at the rate of inflation and population growth, except in national emergencies.
* Reduce Government spending; if it was the same share of GDP as it was in 2005, Act wants the savings to be put towards cutting the top personal tax rate to 25 per cent and the company tax rate to 12.5 per cent.
* Reduce bureaucracy, particularly changing the Resource Management Act and the Local Government Act to loosen the control local authorities have over development.
* Axing the Emissions Trading Scheme.
* Giving parents more choice in which school to send their children, and publishing more information about school, teacher and pupil performance.
* Promote cross-party support for changes to NZ Superannuation; Act believes the timetable proposed by the Retirement Commissioner of raising the eligibility age to 67 is too slow.
* Enshrining the right to self-defence in the Bill of Rights Act, and taking a no tolerance stance on minor offending by youths.
* Abolishing Maori seats in Parliament, Maori wards on local authorities, and special consultation rights for Maori.
* Reaching out to Frank Bainimarama and rebuilding the relationship with Fiji
The last policy is considered a pitch to the New Zealand-Fijian vote.
"We've come to the conclusion, after extensive talks with Fijians now living in New Zealand ... that our present policy of holding the Bainimarama regime at arm's length is not working for New Zealand or for Fiji," Dr Brash said.
Mr Banks arrived at the launch to little fanfare. He sarcastically thanked the audience for the enthusiastic welcome, and then walked out and back in to wild cheers and a standing ovation.
John Boscawen was the only currently sitting MP to attend the launch.