If the High Court rules Labor senator Katy Gallagher ineligible to sit in parliament due to her dual citizenship, it would change a law that has applied for decades, one of her colleagues argues.
The court could throw the opposition's budget response off kilter when it decides on Wednesday whether Senator Gallagher took all possible steps to renounce her British citizenship.
"If the High Court changes the law that has applied for the last 20 years, obviously all political parties will have to consider the implications," Labor MP Tim Watts told reporters in Canberra on Tuesday.
Three other opposition MPs - Josh Wilson, Justine Keay, and Susan Lamb - remain under a similar dual-citizenship cloud as Senator Gallagher.
But any adverse ruling against Senator Gallagher would not force the party's hand on the trio's future, deputy opposition leader Tanya Plibersek says.
There is speculation Senator Gallagher could re-enter parliament through a new lower seat in the ACT if the High Court rules against her eligibility.
"She is an enormously talented asset for the Labor party and we will do everything we possibly can to see that she has the long career ahead of her that she deserves," Ms Plibersek told reporters in Canberra.
