17/10/2016 1:05 PM AEDT | Updated 17/10/2016 2:06 PM AEDT

Another Senator Resigns From The Senate Just Months Into New Term

SA Family First Senator Bob Day resigns after his business went into administration.

Bob Day, bottom left, in the Senate

CANBERRA -- South Australian Senator Bob Day has announced his resignation from the upper house just months into the new parliamentary term.

Day, of the Family First party, nabbed the 12th senate spot in SA at the July election. The senator has been under pressure over his business dealings in recent weeks, with his Home Australia construction business going into liquidation on Monday. The Huffington Post Australia has confirmed Day will be leaving the senate.

Day was granted a leave of absence from the upper house to deal with the business troubles, with claims that the company had been slow to pay contractors and thus delayed construction on homes in NSW and Victoria. SBS also reported that 20 customers of Huxley Homes, one of the companies under the Home Australia umbrella, complained to Fair Trading bodies in the leadup to the July poll.

On Monday, McGrath Nicol announced it had been appointed as liquidator of Home Australia. McGrath Nicol said it would "work constructively with relevant insurers and customers in an effort to facilitate the orderly recommencement of construction of uncompleted homes by alternative builders" and would "communicate with customers in writing in the coming days".

Day himself has told journalists that his position is "untenable" and he will look to repay his business debts.

Day is the second senator to quit the upper house since the election, with Labor's Stephen Conroy also leaving just weeks ago. Day's resignation may cause another headache for the government; he was tightly aligned with the government and an almost guaranteed supporter for Malcolm Turnbull's legislation. Day's resignation will mean that the Family First party will select another of its members to join the upper house, who may not be as sympathetic to the government's agenda as his predecessor.

In a senate where the government has just 30 members and needs to corral at least nine crossbenchers to pass its legislation, losing a strong supporter like Day might make their situation even more difficult.

It is unclear who Family First will choose to replace Day, but Lucy Gichuhi was the number two candidate on Family First's ballot paper at the July election.

Liberal Democrats senator David Leyonhjelm told HuffPost Australia that Day was his "wingman", a "very good guy" and a "decent fellow". LNP Senator James Paterson also paid tribute to Day in wake of the news.

More to come.