Three senators have been sworn in to parliament, meaning there's more new faces than sitting days left before the election.
Tasmanian Liberal Wendy Askew on Tuesday replaced her brother David Bushby on the government benches, shortly before Labor's Raff Ciccone took his place on the opposite side of the chamber.
Senator Ciccone has taken Victorian factional ally Jacinta Collins' spot in the Senate and at the top of the ALP's upper house ticket for the May election.
The Liberal Democrats' Duncan Spender has taken the place of his former boss David Leyonhjelm, who is on track to make a successful switch to NSW state politics.
While Senator Askew isn't up for re-election and Senator Ciccone is all but certain to be returned, their new crossbench colleague could face a tougher task to extend his stay in parliament.
Senator Spender is facing an uphill battle to win the seat, but told AAP on Monday he is determined to make this week count - even if it is his last.
With the upper house due to rise on Wednesday, unless Senator Spender wins his seat back he'll hold the record for least sitting days for a senator, at two.
