Confusing rules on hardware stores' Sunday trading hours will be addressed by the WA Government this year, says Premier Colin Barnett.

In WA, most Bunnings stores open at 7:00am on Sundays but the products they can sell and at what times are consequently restricted.

Its major competitor Masters opens its stores later on Sundays - at 11:00am - which enables it to stock and sell a broader range of products, including whitegoods.

Mr Barnett cited hardware stores as the main focus when asked to expand on comments he made in Parliament this week flagging Government plans to address anomalies in trading hours regulations.

"Mainly around the hardware trade in terms of opening times on a Sunday morning," he said.

"For example, the trade itself, builders and contractors and the like have one set of rules, the public has a different set of rules and it's confusing.

"We are looking to try and remove a discrepancy that relates to hardware stores."

While the Government plans to bring legislation in this year to iron out the hardware trade anomalies, it cannot say when it will be introduced.

Sunday trading rules 'totally outdated': Chamber of Commerce

Chamber of Commerce and Industry CEO Deidre Willmott welcomed the news, saying the rules on hardware stores were totally outdated.

"They actually have a restricted list of products that they can sell," she said.

"That list is out of date and in no way fits in with modern living, so yes, we would very much welcome changes to the rules surrounding hardware stores.

"To be a hardware store that can open at 6:30 in the morning and stay open until 11 o'clock at night, that store can only sell a restricted list of products.

"That means they can sell kitchen goods but not electrical goods, light fittings but not decorative lights."

Wesfarmers owns Bunnings and its finance director Terry Bowen has given the Premier's comments qualified support.

He said it was not as simple as changing Sunday opening hours.

"Along with trading hours...you have to look at the products you're allowed to sell on these days as well," he said.

"We've invested significantly in Bunnings in an offer that's quite different in WA to other states to be able to open at the time we do, and if others aren't open it's because they haven't made that investment.

"So if you just normalise trading hours and not address also the product anomalies which are as big as the trading, then that would be a mistake.

"That would penalise some retailers and not others.

"So I think this is multi-faceted, not just changing times of day.... some of the laws around what you can sell at certain times of day are ridiculous and so they need looking at."

On the issue of general trading hours for all shops on Sunday, Mr Barnett again ruled out extending the current allowed opening time from 11am to 9am.

The ABC understands that when the issue of Sunday trading was discussed at a recent meeting of Liberal MPs in Busselton, at least one MP argued in favour of a 9:00am start time, but some colleagues argued against any extension, fearing the impact on small business.