Given the Turnbull government only has a one-seat majority in the lower house, the immediate stakes of the challenge to David Gillespie's eligibility are as high as they could possibly be.
After all of the legal controversies of the past year we have ended up in essentially the same position – the Senate will include a One Nation senator from Western Australia, but not Rod Culleton.
The Rod Culleton saga still has some way to go before its conclusion. But it is almost certain that he will not be able to continue as a senator.
Biting insults have been exchanged as Western Australian senator Rod Culleton splits from Pauline Hanson, ahead of the High Court determining whether he will be turfed from parliament.
Pauline Hanson has unleashed a new attack on her rebel senator Rod Culleton, declaring that things had 'gone to his head'.
Tensions between Pauline Hanson and her beleaguered One Nation senator Rod Culleton have been on open display this week, raising the question of whether the party will be able to hold it all together.
When micro parties that include politicians we might charitably call "characters" suddenly get clout, things are likely to go badly.
Pauline Hanson has backed the referral of her Western Australian senator Rod Culleton to the High Court to determine his eligibility to sit in parliament, declaring it a matter of integrity.
The departure of up to two crossbench senators and the uncertainty over who might replace them is giving the government fresh obstacles in their efforts to pass legislation.
Malcolm Turnbull laughs off the suggestion that this week's extraordinary developments mean the Senate is in chaos. Okay, let's humour the Prime Minister.
Further uncertainty has been thrown over the Senate crossbench, with the government now moving to have the High Court determine whether One Nation's Rod Culleton was ineligible for election.