"I want to be the voice for those who feel disempowered by the system," Mrs Biddle said.
"I have witnessed many people struggling and it's not only the ones that live on the streets.
"I've witnessed elderly and beneficiaries being ignored, working families struggling to put kai on the table and areas in the health sector that fall short of caring well for their patients because the budget is at the forefront of the decision-making."
She said she was committed to ensuring all people of Rotorua were served under the guiding principles of manaakitanga and rangatiratanga.
"I'm not a person to stand down and I'm very strong in my beliefs. I want to make a difference and continually advocate for those who come to me."
She said she wanted to make a serious challenge, not just look at gaining more party votes for her party.
"It's all about the kaupapa and I'm saying what's good for Maori is good for everyone.
"Todd [McClay] is in a different league from me ... but my stand is to speak to the kaupapa... using the principles of our party."
Maori Party president Tukoroirangi Morgan said the party was excited to have Mrs Biddle on board.
"The work she does for our people, including homeless whanau, is to be admired and respected," he said.
"There's a saying that when you educate a man, you educate a man, but that when you educate a woman, you educate a generation. And if we're to ensure that we eliminate homelessness and poverty in this country then we need staunch and passionate women like Wendy."
Mr Morgan said the Maori Party was standing 15 candidates so far in general seats throughout the country.
"This is a timely reminder that even non-Maori can vote Maori Party," he said.
"We are a party for Aotearoa which seeks the wellbeing for all peoples of this land."
