He told board members this week they needed to be mindful of making submissions on council-led big-ticket proposals for Wanaka, such as a proposed indoor sports centre, as they could run the risk of being accused of predetermination.
"Even the perception of predetermination could affect the final outcome of council decisions," Mr Field said.
His comments came from left field during a meeting of the community board in Wanaka, on Tuesday.
However, Wanaka Community Board chairman Lyal Cocks said Mr Field was there to provide legal guidance and advice about meeting standing orders and the board's role.
Board members take an oath of impartiality - alongside a commitment to represent Wanaka to the best of their abilities - when sworn in as community representatives.
As part of their duties as council representatives, they join local residents' associations and community groups, to provide an important link with such informal bodies, and report back to the other members of the community board.
Mr Field said if board members made individual public submissions, they could overstep the mark as impartial representatives on community groups, and be perceived to have predetermined outcomes.
"If you make a public submission, then you need to declare it, or take yourself out of the middle role when coming from some outside delegation," he said.
Wanaka Community Board chairman Lyal Cocks said Mr Field's comments had provided guidance about the board's role regarding its role in upcoming deliberations for the proposed multimillion-dollar indoor sports centre and aquatic facility.
Board members had considered tabling and filing a joint submission on the proposed sports centre, but if they had done so they would have ruled themselves out of any further part in deliberations, Mr Cocks said.
"We would have effectively subverted our role and responsibilities to represent and make future decisions on behalf of Wanaka regarding the proposed sports centre," Mr Cocks said.
"If the board want to make a submission, then they can't be involved with the decision-making," Mr Field clarified to the Otago Daily Times when approached later.
