SA shield law passes upper house

A shield law allowing journalists to protect their sources has passed the first hurdle in the South Australian parliament.

The Liberal Party bill, which brings SA into line with other states, passed in the upper house on Wednesday night and ensures journalists are not forced to reveal confidential sources unless there is a clear public interest to do so.

"Whistleblowers need to be supported when they come forward. Without this protection whistleblowers may be intimidated into silence," deputy Liberal leader Vickie Chapman said.

The bill now goes before the lower house but is not expected to be supported by the Labor government.