Fears pregnant women, young children, and babies could be affected if homes are built too close to an industrial strip in Perth's south are behind plans to introduce laws to enforce a buffer zone, the WA Premier says.

Labor is set to oppose the move, with Opposition Leader Mark McGowan strongly insisting his stance was not linked to property developer Nigel Satterley's opposition to the legislated buffer or his financial support for the ALP.

Mr Satterley, chief executive of the Satterley Property Group, said tests showed there were no health concerns for residents around the Mandogalup land near the Kwinana industrial area, where he wants to develop a housing project.

He also rejected suggestions he had influenced Labor's position, and said he donated to both major parties with no expectation of anything in return.

A buffer zone currently exists around the area to keep heavy industry and residential communities apart.

But the Kwinana Industries Council wants the zone to be protected by law, and argued existing planning rules covering the buffer were weak, and it was under constant attack from developers and local government.

Buffer needed to protect residents: Barnett

Yesterday, Mr Satterley wrote to Government ministers and MPs stating his "strong objection" to the draft Western Trade Coast Protection Area legislation and an "extreme and unwarranted" 1.5-kilometre extension to the buffer.

Mr Satterley wrote that as well as the lack of health or environmental risks, the buffer would be retrospective and "seriously impinge" on people who had already bought land at Mandogalup.

But Premier Colin Barnett said the legislation was being prepared and would be introduced after the parliamentary winter recess.

"If we allow residential development to occur close to industry we've got to be conscious of what impact could there be on pregnant women, young children, babies," Mr Barnett said.

He said commercial properties could still be built on the private land.

Mr McGowan was adamant the legislation would be a mistake.

"We've had a consistent position in relation to this legislated buffer zone and that is that it's not needed," he said.

"It will adversely impact housing prices, adversely impact people and it doesn't follow proper planning guidelines."

Developer denies driving Labor's stance on issue

Mr Satterley has denied influencing Labor's position on the buffer zone. ( ABC News )

Mr Satterley has accused Mr Barnett and Treasurer Mike Nahan of "mismanaging the economy" and expressed disappointment there was no land tax relief in the recent State budget.

Earlier this month, he also claimed Dr Nahan was orchestrating a leadership spill against the Premier.

The property developer attended a dinner recently to farewell retiring Federal Labor MP Gary Gray, where he reportedly introduced Mr McGowan at the event as "the next premier of WA", something he denies ever happened.

On June 16, the developer will co-host a $1,000-per-head ALP fundraiser to be attended by former federal Labor leader Kim Beazley and Mr McGowan.

And last week Mr Satterley and Mr McGowan were at a Mandogalup residents meeting.

Mr McGowan today said he was not sure if they had discussed the buffer then, but Mr Satterley said they did.

Mr Satterley told the ABC Mr McGowan first approached him "some time ago" to discuss the issue and they had talked about it four or five times since.

But he said he had not influenced Labor's stance.

"No, because we are funding Liberal functions ... we support both sides of politics, including the Nats," he said.

"You have to work with the Government of the day and this doesn't come into it."