But following an independent assessment, the tribunal discovered Poananga "attempted to skew the results of her tests''.
"Unfortunately, the practitioner's behaviour around the medical assessment did not reflect well on her fitness to be a legal practitioner,'' Judge Clarkson said.
Poananga served three terms - nine years - on the Gisborne District Council as representative for the Matakaoa ward at the top end of the East Coast. In the 2010 election she stood for the city ward and was not elected.
She was on Tairawhiti Health Board for three terms and ran for the Maori Party in 2005.
She was contracted to work for a law firm in Auckland specialising in Treaty of Waitangi claims.
The workload increased after the Treaty of Waitangi Act was amended in 2006, meaning that after September 2008 no Maori could submit a new claim to the Waitangi Tribunal.
Poananga said pressure led to her misconduct, because she was responsible for about 35 claims covering much of the North Island.
She said she had authorisation to place her signature on the applications by some of her clients but in one case later admitted she was not authorised to act on a claimant's behalf at the time.
The electronic signature was placed there by her personal assistant, she said.
In another incident, Poananga placed a claimant's signature in her own hand on his legal aid application and later filed an affidavit saying the signature was the client's, knowing that was untrue.
She also submitted 17 legal aid forms in 2008, placing the signatures of other people on each form. Each application contained a statutory declaration and she signed them knowing they were false.
Poananga's counsel Mr Y Singh said her "primary concern was to help her people and that no harm had been caused to anyone as a result of her offending''.
Representing the Standards Committee, Ms G Phipps said relevant mitigating features included her good character, reputation, absence of prior transgressions and eventual acceptance of the facts and indication at a relatively early stage of a guilty plea.
Aggravating factors included an absence of remorse, failure to accept responsibility and showing no insight into her behaviour.
Mr Phipps said it was a "clear case of dishonesty'', and the repeated nature of the conduct was clearly aggravating.
Judge Clarkson said Poananga had come under a high level of work and financial pressure when the offending happened but her situation was not unique.
The fact she could not find a legitimate method to deal with the problems she faced in getting the necessary signatures was a strong indication of her struggle to meet the level of competency required, he said.
"We consider the lack of integrity demonstrated by the misconduct in this matter, particularly when accompanied by failure to recognise it as such, means strike-off is the only proper response in order to protect the public and the reputation of the profession.''
The decision was reached unanimously by the five tribunal members.
A New Zealand Herald report from 2001 described Poananga as the "militant face of the 70s and 80s Maori nationalism movement''.
In 1985, she caused controversy with her remarks about "the riff-raff, flotsam and jetsam of British culture'' and that Pakehas should leave New Zealand or accept Maori sovereignty.
She caused a "stir'' on both sides of the Tasman that year when she delivered a paper on decolonisation at a conference, including comments that whites in Australia and New Zealand should return to their ancestral lands.
Poananga spoke about working to promote Maori nationalism: "We say colonialism everywhere must be repudiated and destroyed. We as Maori must reclaim our heritage as the tangata whenua (first people of the land).''
She was dismissed from the Ministry of Foreign Affairs in 1982 after refusing a transfer to another department. At the time she said she was fired for being "too Maori''.
