'I am now Citizen X, not Senator X': Xenophon officially quits Senate

Nick Xenophon has officially resigned from the Senate, sparking a casual vacancy for his seat.

Crossbench senator Nick Xenophon has officially resigned from the Senate.

He intends to run for a South Australian parliament lower house seat at next year's election.

"I am now Citizen X, not Senator X," he said in a statement on Tuesday.

MORE TO COME.