Mrs Dean is now scheduled to take a proposal to the National party caucus on Tuesday, regarding a move which will address Easter shop trading issues at a Queenstown Lakes district-wide level.
Rotorua MP Todd McClay's private member Bill, which would have given retailers the choice of trading on Easter Sunday, was lost by three votes with Parliament opting 62-59 to retain the status quo.
Both Wanaka Chamber of Commerce president Leigh Stock and Mrs Dean were disappointed at the decision.
The pair were now considering their next move, Mr Stock said.
A "strong union view" had held sway - particularly over Labour's MPs - and influenced the voting in Parliament on Wednesday night regarding Mr McClay's Bill, Mrs Dean said.
"I'm very frustrated by the defeat and don't believe the objections raised about workers being compelled to work during Easter hold for Wanaka," Mrs Deans said.
Local Wanaka businesses and their retail workers were "dynamic," "flexible," and well used to tailoring their trading hours towards tourists, visitors, and large Easter events, such as the Warbirds Over Wanaka airshow.
Discussions with Mr Stock had centred on the need to address the "local" anomalies within the Lakes district, which allows Queenstown retailers to trade while Wanaka businesses are prohibited from doing so, she said.
The National Distribution Union, which represents retail workers, has backed the move to keep the Easter holidays free from shop trading.
NDU Acting General Secretary Karl Andersen said he hoped the defeated Bill would finally mark the end of constant attempts by MPs to liberalise shop trading.
Mr McClay's private Bill is the 10th attempt to amend Easter shop trading laws that has been voted down by Parliament in the past 20 years.
The next biennial Wanaka Over Warbirds airshow, which brings tens of thousands of visitors to the area, will be held at Easter next year.
