The One Nation leader announced her surprising decision on Monday after the government took unprecedented legal action against her West Australian colleague Rod Culleton and Family First's Bob Day.
The High Court sitting as the Court of Disputed Returns will determine whether Senator Culleton had been ineligible to run for parliament because of an existing larceny conviction.
Senator Culleton had been convicted in March of stealing a tow truck key - a larceny charge which carries a maximum sentence of five years in jail.
Under the constitution, anyone convicted of a charge carrying a jail sentence of a year or more is not eligible to run for parliament.
He won a WA Senate seat for One Nation at the July 2 election.
On August 8, Senator Culleton's conviction was annulled, and on October 25 he pleaded guilty to the charge with the magistrate finding the charge proven, but dismissing it.
Embattled One Nation senator Rod Culleton earlier said he will continue to vote on legislation, despite previously saying he would abstain.
He told parliament on Monday he had accepted advice from the Senate Clerk that he had the right to continue to exercise his vote while the court considered the matter.
