The High Court has ordered another special recount of the votes in the Senate seat former Nationals deputy leader Fiona Nash was forced to vacate because of her dual citizenship.

Key points: Hughes declared ineligible to take Nash's spot because she took government job after 2016 election

Hughes declared ineligible to take Nash's spot because she took government job after 2016 election Nash found ineligible over different section of constitution regarding dual citizenship

Nash found ineligible over different section of constitution regarding dual citizenship Molan expected to be announced after AEC recount on Wednesday

Solicitor-General Stephen Donaghue QC raised concern about a recount, given that the High Court is still yet to deliver its official reasons for finding Liberal candidate Hollie Hughes ineligible to take up the Senate spot.

He asked Justice Stephen Gageler to hold off in making final orders about how to replace Ms Nash until those reasons were published.

The Solicitor-General's qualification reflects a possibility the former deputy Nationals leader could make a political return.

If Ms Hughes is deemed ineligible to hold office from the time of the last election, the recount would be ordered.

But if the High Court's reasons suggest her decision to take a taxpayer-funded job only ruled her ineligible after that date, it could allow a "casual vacancy" be ordered, paving the way for Ms Nash's return.

ABC election analyst Antony Green said Liberal candidate Jim Molan, the seventh person on the Coalition's ticket, would be elected if the recount was necessary.

Mr Molan is a former senior Army officer who has emerged as a high-profile Liberal conservative in recent years.

He was head of the Australian Defence College, and served as chief of operations for coalition forces in Iraq.

The retired major general then helped design the Liberal Party's border protection policy, dubbed Operation Sovereign Borders, before the 2013 election.

Since then, he has been active in the Liberal Party's internal wars, fighting alongside conservatives like Tony Abbott for changes within the New South Wales branch.

Mr Molan was dismayed at being placed in the unelectable seventh spot on the NSW Liberal-Nationals joint ticket in 2016.

At the time, he retweeted someone who said: "NSW Liberals are a dumpster fire of factional muppets that put General Jim Molan at no 7."

Nash hoping for casual vacancy instead of recount

The Senate recount is expected to be carried out on Wednesday by the Australian Electoral officer for New South Wales.

Ms Hughes was identified as the replacement from a recount after the High Court's citizenship ruling on the former deputy Nationals leader.

Fiona Nash and Hollie Hughes were both found ineligible to serve the Parliament under different parts of the constitution. ( AAP/Supplied )

But questions were raised over whether she was eligible because she took a government job on the Administrative Appeals Tribunal after losing the election.

She was disqualified last Thursday.

Late last month, the High Court ruled Ms Nash ineligible to sit in the Senate, as her father was born in Scotland.

The decision leaves open the possibility Ms Nash could return to the Upper House.

Green said the overwhelming majority of the Coalition's Upper House votes were above the line votes for the party.

"So there is no leakage of preferences in this recount, they will just go straight down the ticket, and Jim Molan, being next on the ticket, wins the seat," he said.

Editor's note: An earlier version of this story did not reflect the request by the Solicitor-General to defer any decision on replacing Ms Nash until after the High Court delivered its reasons in the Hollie Hughes case. It has been updated to include that detail.