Barnaby Joyce says the High Court case testing his eligibility to sit in parliament was forced on him by "malicious fate" and is being used by some to "open wounds".
The deputy prime minister is one of seven federal politicians facing an anxious wait to find out if they will be disqualified over their citizenship status.
Arguments were put to the full bench - sitting as the Court of Disputed Returns - over three days last week, with Chief Justice Susan Kiefel noting a decision needs to be handed down as soon as possible, with or without reasons.
Mr Joyce, writing in his electorate's main newspaper - Tamworth's The Northern Daily Leader, said an outcome probably would not be known until the end of coming week.
"I hope for the best but prepare for the worst," he said on Saturday.
The Nationals leader, the only MP in the lower house in the case, stressed he never wanted it to get to this point.
"It was forced on me by malicious fate and others have used this to open wounds and play a very poor game," he wrote.
He acknowledged many were angry that the fact his father was born in New Zealand could send his seat of New England to a by-election.
"But that is the law and we deal with it," Mr Joyce wrote.
"I hope we have a line of sight as to where this all ends within a week but that is in the hands of others so much better qualified to deliberate than I could ever hope to do."
Malcolm Turnbull's one-seat majority in the lower house could be at risk if Mr Joyce is disqualified.
His political nemesis Tony Windsor, who formerly held the seat as an independent, joined the High Court action to against Mr Joyce.
It is unclear whether he will contest a by-election if one is called.
