The Act Party has done a complete flip-flop and now supports a proposed ban on gang patches in Wanganui, abandoning its bedrock philosophy of personal freedom in favour of a new hardline law-and-order agenda.

Act voted for the ban despite leader Rodney Hide previously saying it was "rubbish" that it could never support because it would breach people's fundamental rights to wear what they wanted on a T-shirt.

Mr Hide said that while he objected to the ban "on principle", the party had flip-flopped to try to get National's support for its proposed "three strikes and you're out" law. He denied it was part of a deal.

The patch ban is now set to become law after passing its second reading with National, Act and United Future's support.

At its first reading in April, Mr Hide told Parliament he would happily vote against the bill because it was against the principles of freedom.

"Freedom is about the individual, and the measure of a free society is how we move to protect the minority from the majority. If the majority thinks that people wearing glasses should be locked up, that is not freedom or democracy," he said.

Act's support was given at the second reading by new MP David Garrett - the former legal adviser to the Sensible Sentencing Trust who designed the three-strikes policy, under which those convicted of a third violent offence would be sentenced to life in prison with a 25 years' non-parole period.

Mr Garrett was not even a member of Act before being approached to stand shortly before the election. He was its "mystery candidate". His high list placing was an arrangement between Mr Hide and Garth McVicar of the Sensible Sentencing Trust.

Mr Garrett is a hardliner who this week told the Herald that if three strikes was found to breach fundamental human rights, the solution was to change the Bill of Rights.

He dismissed the report by Attorney-General Chris Finlayson that found three strikes apparently breached the right protecting New Zealanders against cruel, degrading or disproportionately severe punishment.

Mr Garrett said the report had been prepared by "some oik in Crown Law".

He told Parliament that the ban on patches was a "good second step" to banning gangs altogether.

Three strikes has been introduced to Parliament by National as a condition of the Act Party's agreement to support it as Government. Act's flip-flop on the gang-patch ban was put down to being part of a deal after Mr Hide told the Back Benches television show: "We voted for it [the patch ban] because what it's going to do is get three strikes through this Parliament."