A legal battle is already under way over last year's decision to cut funding from $1.2 million to $900,000 - a judicial review was heard in the High Court in Auckland last week and the decision has been reserved.
The trust also said it would write to Auditor-General Lyn Provost asking her to investigate the funding board over allegations it receives free tickets to arts events without declaring them.
It came after funding board chairman Vern Walsh admitted the board did not follow written or other publicly available criteria in allocating its funds, which have totalled $66 million since 2010/11.
He also confirmed to media the board does not hold records of which members receive gifts from the amenities it funds, which include the Auckland Philharmonic Orchestra, the Auckland Theatre Company, New Zealand Opera and the Auckland Arts Festival.
Instead, gifts under $150 are declared at the beginning of meetings. Gifts exceeding $150 cannot be accepted by board members.
The Auckland Philharmonic Orchestra and the Auckland Theatre Company have confirmed they provided free tickets to board members.
Auckland Rescue Helicopter Trust chairman Murray Bolton said the fresh litigation made clear "we will no longer tolerate this funding board's biased decisions".
"We will sue them every year until our funding is restored to a level at least proximate to that mandated by Parliament in 2008."
Act's Epsom MP John Banks said the board's treatment of the trust was "shabby".
"Every citizen has an interest in this service and can at any time be a beneficiary from it," the former Act Party leader said.
Auckland Council has the final say on funding and will decide at a meeting on March 27.APNZ
The trust was yesterday told its 2014/15 grant would be cut to $450k by the Auckland Regional Amenities Funding Board. Photo / NZ Herald