Industrial action will see most Southlink buses servicing the north, south and hills areas of Adelaide cease running between 10:00am and 2:00pm today.

The stop work action is a crescendo of fruitless negotiations that had been underway since mid-last year according to Transport Secretary Union secretary Ray Wyatt.

Industrial action between drivers and a second company, Light City Buses, has been postponed after negotiations and a financial assistance package from the State Government has brought all interested parties back into negotiation.

"This other company [Southlink] has a totally different industrial relations system which basically doesn't allow anybody to come there unless they want to come in on their days off," Mr White told 891 Breakfast.

Opposition transport spokesperson Vickie Chapman said the current strike action was a direct result of inaction from the government from the beginning of the disagreements.

When negotiations broke down on 22 January 2014, confusion was created over which minister would comment, with Transport Services Minister Chloe Fox and Transport and Infrastructure Minister Tom Koutsantonis not wishing to comment and Industrial Relations Minister John Rau stating the dispute was between the drivers and the company and not an issue for the government to become involved in.

"Finally the Government put out John Rau to say this is an industrial relations matter, we will now address this issue," Ms Chapman said.

Industrial Relations Minister John Rau said the government had contributed $100,000 each year for the next three years to help aid the contractors settle pay disputes, and deployed additional transport police.

"I became involved when this became an industrial dispute," Mr Rau said.

"The real issue at the moment is to resolve the dispute."

Transport Workers Union secretary Ray Wyatt said the company would be attempting to cover temporarily cover the routes with non-union staff, but he "would be concerned; there is no certainty of a bus showing up."

Impacted routes include the areas of Sellicks Beach, Noarlunga, Elizabeth, Smithfield, Stirling and Mount Barker.

A list of specific route numbers affected can be found here.