Drivers who illegally use a parking space for people with a disability in South Australia could soon be issued with a demerit point in addition to a fine under a new plan.

The State Government has backed the laws proposed by Dignity for Disability MLC Kelly Vincent, and is investigating ways to implement the change.

Ms Vincent said the existing fines system was not a strong enough deterrent with her office receiving many complaints about the "very common problem".

"I think people will think twice if they are to risk getting a demerit point, particularly if they are a younger driver who might not be on their full licence and can't afford to lose demerit points," she said.

"It will send a stronger message and I think that has been the experience in New South Wales where these laws have been introduced.

"It is important to remember this is not about convenience.

"This is about someone who may or may not use a wheelchair or mobility aid or may not be able to walk very far to get to a particular venue ... it is also about safety."

Ms Vincent said people in wheelchairs were less visible in car parks due to their seated position which could create risks if a disability park was not available.

She also noted some people who used wheelchairs and aids needed to ask strangers to back their cars out of regular parks because there was not enough room to allow them to put their equipment in the car.

Ms Vincent said the State Government was in discussions with local governments about how to implement the changes.

It is hoped the new law will be in place next year.