Dastyari told 'go back to China' in Senate

He's been incognito since resigning from the Labor frontbench, but Sam Dastyari has popped up in his most comfortable battleground - a Senate inquiry hearing.

The senator dubbed "Shanghai Sam" by the government after a controversial Chinese payment left him relegated to the backbench, returned to the familiar inquiry setting on Friday.

He was there to grill the attorney-general on a controversial decision to change legal advice directions to ministers - something with which his side is gunning for George Brandis' head.

But it wasn't long before Senator Dastyari was reminded of his own controversy.

"You should go back to China," Liberal senator Ian Macdonald told him.

So Senator Dastyari took to another favourite medium: Twitter.

"Senate hearing and the conduct of Sen Macdonald and Sen O'Sullivan is just embarrassing. Bullies. Shades of Triggs," he wrote.