Drivers who use disabled parking spaces illegally should lose demerit points as well as face a fine, South Australia's Dignity for Disability Party says.

MLC Kelly Vincent plans to introduce a private member's bill seeking the harsher penalty.

She said a threat of losing demerit points and possibly their driver's licence would make drivers think twice before parking illegally in spaces other people are heavily reliant on.

"The misuse of these car parks by people without a permit is rife," she said.

"It is clear to us that unfortunately the sole pecuniary offence - the fine - is not getting the message across."

Ms Vincent said it was important to ensure all drivers considered the needs of others.

"We want to introduce a demerit points offence to really get the message across that you're not just being inconsiderate, you are breaking the law and taking away potentially someone's ability to access their community easily and safely," she said.

"Given that public transport in 2015 remains largely inaccessible to people with disabilities, many have no choice but to use a private vehicle going from place to place, whether it be to the shops, to work or other community and social events.

"It's not just about inconvenience, it may be that the disabled person needs the extra space to get a wheelchair, walking frame or other mobility aid out of their car easily. We need to get the message across that this is not about special treatment."

She said it was disappointing councils and private car park owners did not more frequently police disabled spaces and some had even painted over the spaces to allow both disabled parkers or anyone else who just wanted to stop for five or 10 minutes.

Ms Vincent said the addition of demerit points to disabled parking space breaches had now been implemented in New South Wales.

She said it was early days there but the community response since the change appeared to have been positive.

The Dignity for Disability MLC said her next step would be to speak with parliamentary colleagues from all parties but she was confident of enough support for the legislation to pass.