THE South Australia's been accused of pulling out of a Senate inquiry hearing related to the basin deal with Prime Minister Julia Gillard.

The Senate committee inquiry is taking evidence on two pieces of legislation relating to last month's announcement of plans to return 3200 gigalitres to the Murray Darling Basin.

Coalition Basin spokesman Senator Simon Birmingham said until yesterday, the SA government was scheduled as the opening witness at the Adelaide hearing today but has withdrawn at the last minute.

"It's all very well for (Premier) Jay Weatherill and (Prime Minister) Julia Gillard to be enthusiastic about a press release devoid of any detail, but they should also be willing to explain whether the resultant legislation actually delivers on their hype," he said in a statement.

"Just last week Jay Weatherill big-noted himself by calling a press conference outside Christopher Pyne's electorate office, knowing full well he was in Canberra, calling on all SA Liberal MPs to support legislation he now refuses to explain."

Mr Weatherill said the time for talk was over.

"All federal MPs should get on with passing this legislation," he said.

A SA government spokesperson said the government only received an invitation to the inquiry on Tuesday and responded saying it would provide a written submission to the inquiry.