Cr Karen Arnold announced her intention to resign following a meeting over the contract on Wednesday.
The extraordinary meeting was predominantly focused on the controversial Wastenet contract, which has been held by Southland Disability Enterprises(SdE) for the last eight years.
Invercargill Mayor Sir Tim Shadbolt used his casting vote on Wednesday night to vote against a recommendation to take the contract away from SdE.
This is despite documents released by the Southland District and Gore District Councils showing that awarding the contract to another provider could have saved $11 million over the next 16 years and produced a new automated facility.
Cr Arnold said while resigning had crossed her mind, it was Cr Toni Biddle's motion to bring the debate and discussion into the public that confirmed her intention.
She said, specifically regarding the WasteNet contract, she had lost confidence in the current council's decision making process.
The vote on whether to approve the recommendation given to council on the preferred tenderer was motioned to be made in public, after there was concern over lack of transparency.
The votes from councillors for and against the motion and recommendation were evenly split and were decided by Sir Tim.
The result was for ICC to go against the recommendation.
Councillors listened to legal advice regarding making information public during a live tender process, which is the reason why information had so far been kept under wraps.
Cr Arnold said it was about principle - "to make good decisions you have got to follow process."
Following the meeting, in a press release from Gore District mayor Tracy Hicks and Southland District mayor Gary Tong said they "have serious concerns about the tender process to award the contract for processing the region’s recycling".
Earlier this week Southland and Gore District councils voted unanimously at separate meetings to adopt the recommendation from WasteNet.
"It was a tough decision but Southland District and Gore District Councils were confident in the advice they were getting from WasteNet on all aspects of the process to date,” Mayor Hicks and Mayor Tong said.
With Cr Arnold being on the WasteNet advisory group, she said she would be taking advice from chief executive Clare Hadley.
"I don't want to jump ship early and compromise that."
