05/04/2017 11:11 AM AEST | Updated 06/04/2017 9:15 AM AEST

Bob Day Is Done, So Who Will Replace Him?

The Full Bench of the High Court says his election was invalid.

Alex Ellinghausen/Fairfax
Former Family First Senator Bob Day puts his jacket on... to go home.

CANBERRA -- Bob Day has been found to have been invalidly elected, but it is a major mystery as to who will replace him in the Senate.

The second on the Family First ticket? Or another Nick Xenophon Team senator? Perhaps another Coalition senator? Or Labor?

The favourite is firming as Family First's number two, Kenyan-born lawyer Lucy Gichuhi, who only received 152 first-preference votes.

Whatever the result, it will have a major impact on the passage of legislation through the federal parliament.

Day was a most supportive and reliable crossbench senator for the Turnbull Government and his vote has been missed.

The full bench of the High Court, sitting as the Court of Disputed Returns, has ruled the former Family First Senator breached the Constitution back in February 2016 and his position should be filled by a special recount of ballot papers.

Day has been found to have breached Section 44 of the Constitution by having an indirect pecuniary interest over the leasing arrangements for his electorate office.

His company had owned the premises which was being rented on behalf of the then senator.

The property was later sold to a family friend, but the Government alleged he still retained a financial "interest".

The Turnbull Government has welcomed the decision.

"This is the outcome the Government sought from the Court," the Federal Attorney-General George Brandis and Special Minister of State Scott Ryan said in a statement.

"This decision confirms the Government took the appropriate action last year by proactively asking the Senate to refer the matter to the High Court. "

What is Section 44?

Section 44 of the Constitution sets out restrictions on who can be a candidate for Federal parliament.

It lists a number of ways a senator may be disqualified, including whether they have allegiance to a foreign power, whether they are a traitor or have been convicted of a crime.

The last clause of the section - whether they are connected to an office for profit – is murky and has not been tested.

It reads:

Section 44 (v.) Has any direct or indirect pecuniary interest in any agreement with the Public Service of the Commonwealth otherwise than as a member and in common with the other members of an incorporated company consisting of more than twenty-five persons.

Day resigned as a senator on November 1 last year, before the High Court challenge, to deal with the collapse of his Home Australia group of companies.

The matter is now expected to return to the High Court in the next few days so that specific orders can be given to allow for the recount, which will be conducted by the Australian Electoral Commission.

Despite Gichuhi being the favourite, without many Family First options, the Senate spot could go to another party.

And while the High Court has been deliberating on Bob Day's election, his senate seat has remained empty leaving the government unable to rely on his usually reliable vote.

The new Senator is expected to be sworn in when the Senate next meets on Budget day, May the 9th.

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