A law labelled archaic by Wanaka retailers remains in place despite several unsuccessful parliamentary Bills which have sought change.
On average, Parliament has voted down Bills seeking to repeal the Shop Trading Hours Act every second year since the first attempt in 1990.
Waitaki MP Jacqui Dean told the Otago Daily Times this week conscience votes from the nation's MPs were the reason why the law remained in existence.
"Because it is a conscience issue, MPs don't vote along party lines.
"They vote based on their own views and those of their constituents," she said.
There was increasing support from a number of MPs, who felt it was time for "further liberalisation" towards freeing up shop-trading restrictions, she said.
However, two lobby groups also influenced some MPs' conscience vote - trade unions, which wanted to keep workers rights from having to work on Good Friday entrenched, and faith-based lobbyists wanting the religious aspect of the holiday observed, Mrs Dean said.
A private Bill from Rotorua MP Todd McClay seeking to amend trading on Good Friday and Easter Sunday was defeated by three votes in December.
Mrs Dean is readying another attempt to change the law - this time in the form of a local authority Bill - after her own private members Bill was defeated 87-34 in May 2007.
The new Bill will seek to extend an existing exemption, which applies to Queenstown and allows retailers there to trade during Easter, to apply across the whole of the Queenstown Lakes district, Mrs Dean said.
Several Wanaka retailers were considering opening at Easter.
"Thousands of visitors are expected to arrive in town for Warbirds Over Wanaka and retailers are quite naturally frustrated that they can't provide a service to those potential customers."
Retailers spoken to by the ODT were tight-lipped about their intentions regarding opening for trade on Easter weekend, citing concerns over attracting the attention of Department of Labour inspectors.
Department spokesman Colin Patterson said its officers would be enforcing the laws in relation to Easter shop-trading laws, but declined to say whether they would visit Wanaka.
Several Wanaka retailers were prosecuted for Easter shop-trading breaches in 2006.
They pleaded guilty and were fined.
Mrs Dean said she had "no view" about retailers who made the individual decision whether to trade or not.
Retailers knew the consequences and had faced them in the past, she said.
She planned to present her new Bill of Order to Parliament in about three weeks.
If it was accepted then it would "probably" take about six months to go through the parliamentary process, Mrs Dean said.
• Yesterday, the Department of Labour advised retailers to ensure they were familiar with the Shop Trading Hours Repeal Act 1990, which specifies three and a-half days each year on which most New Zealand retailers must close - Christmas Day, Good Friday, Easter Sunday and until 1pm on Anzac Day.
While the Act spelled out exemptions, retailers who were not exempt and open for business could be prosecuted and fined up to $1000.
Garden centres had been exempt since the Act was amended in 2001 and were allowed to trade on Easter Sunday.
