Waiting times at South Australian emergency departments will triple if the Abbott Government's $7 GP co-payment is introduced, the SA Health department told a Senate inquiry today.

The Senate Select Committee on Health also heard the South Australian Government was considering a further administration fee of up to $30 dollars to cover the cost of collecting the co-payment in emergency departments.

South Australian Greens Senators Sarah Hanson-Young and Penny Wright have slammed the Coalition's first budget, which slugs SA families while letting big business off the hook.

"This is a brutal budget by a cruel Coalition," Senator Wright said.

"Not only has Education Minister Christopher Pyne turned his back on SA school students by ripping the heart out of the Gonski reforms, he wants to make it harder and more expensive to go to university.