The federal Opposition has voted with Labor in the Senate to defeat a Greens motion that sought to force Government to intervene in legal proceedings against WikiLeaks founder Julian Assange, to ensure he is not subject to extradition to the US.

Shadow Attorney General George Brandis has stepped up Opposition attacks over the appointment of a former Labor political staffer to a $450,000-a-year role within the NBN Company, calling it a "rolled-gold example of jobs for the boys."

Queensland Liberal frontbencher George Brandis has stepped up Opposition attacks on Government over the $450,000-a-year appointment of former Labor staffer Mike Kaiser to the NBN Company, labelling the decision "disgraceful."