Labor leader Bill Shorten says government ministers have a lot of explaining to do over the Bob Day case.
The former Family First senator was found by the High Court on Wednesday to have been ineligible to stand for parliament because he indirectly benefited from a government lease arrangement on his Adelaide electorate office.
The court said it was a "glaring example" of the type of behaviour section 44 of the constitution was designed to prevent.
Mr Shorten, who is on a listening tour of regional Queensland, says ministers were warned about the potential problem as far back as 2014 but failed to act promptly because of the heavy reliance on Mr Day's vote in the Senate.
"I think a whole raft of senior Turnbull allies in the current government need to explain what they knew and when they knew it," Mr Shorten said.
"And when they knew there was a problem, why did they look the other way and let this dodgy deal enter into the unravelling which we've seen - this government really will do anything to stay in power."
Prime Minister Malcolm Turnbull says it was the government that referred the matter to the Senate and then took it to the High Court.
A High Court justice is expected to rule on the special count within days.
The Australian Electoral Commission will then conduct the count, which is expected to elect the second candidate on the SA Family First ticket, lawyer Lucy Gichuhi.
Kenyan-born Ms Gichuhi told the ABC she would bring a "new dimension" to that of Mr Day and wanted to "empower immigrant communities".
Even if Ms Gichuhi is elected, there is doubt surrounding her eligibility for parliament because of her Kenyan citizenship.
Under the constitution, a person cannot sit as an MP if they are "a subject or a citizen or entitled to the rights or privileges of a subject or citizen of a foreign power".
Family First says it's possible the seat may go to either Labor or One Nation, depending on the process used for the special count.
Special Minister of State Scott Ryan is hopeful paperwork will be filed within days to allow the recount.
On the confusion over Ms Gichuhi's eligibility, Mr Ryan said he understood when she became an Australian citizen, Kenyan law automatically took away her citizenship.
"I take at face value the declaration signed by every candidate," he told ABC radio.
