Ross said he is confident party co-leader Billy Te Kahika will win in Te Tai Tokerau and get the party into parliament.
"It is an emotional decision to step back from where it all began as a local representative, but this isn't goodbye," Ross said in a statement today.
"Advance NZ is gaining great momentum, and I have taken on the role of steering our campaign's strategic direction.
"I could not do justice to our 60 candidates, our 7000 members and the thousands of volunteers while also properly running in the three-way contest here on the ground."
Jami-Lee Ross will not contest the Botany seat.
Advance NZ will field a list of more than 60 candidates throughout New Zealand.
Ross said he believed growth in party membership, fundraising, social media reach and increasing volunteer numbers showed the party was growing.
"Billy's energy and connection with voters, combined with my experience in Parliament, will see Advance NZ be competitive on October 17," he said.
Ross won Botany comfortably in 2017, with a majority of 12,839, winning 62 per cent of the total votes cast.
However, he was cast out of the National Party after a high-profile clash with then-leader Simon Bridges and claimed Bridges had broken election funding laws.
Ross was later charged by the Serious Fraud Office, while Bridges, a former Crown prosecutor who denied any wrongdoing, was not charged.
