Mr Dastyari announced his resignation in December but did not immediately stand down, saying only that he would "not return to the Senate in 2018". Parliament is due to return on February 5.

Sam Dastyari announces his resignation from Parliament. Credit:Janie Barrett

By waiting six weeks before resigning Mr Dastyari was able to continue to draw his senator's salary, which amounts to about an extra $20,000.

Labor leader Bill Shorten defended the delay, arguing that a number of other outgoing senators had also taken more than a month to exit the Parliament after resigning.