Blame PM for citizenship mess: Shorten

As voters cast their ballots in a Bennelong by-election caused by the dual citizenship debacle, Bill Shorten insists he will take no responsibility if the scenes are repeated next year.

Liberal John Alexander has been forced to fight for his seat after resigning over his British roots, while constitutional question marks still hang over several politicians, which could trigger more by-elections.

"If the citizenship goes into the new year, you have got one person to blame, Malcolm Turnbull," Mr Shorten told reporters in Sydney on Saturday.

Earlier this month, Labor unsuccessfully tried to refer nine more parliamentarians to the High Court over possible dual citizenship.

The opposition and crossbench voted to send four Labor MPs, four Coalition MPs and crossbencher Rebekha Sharkie to the High Court.

But the motion was narrowly defeated after it was opposed by the coalition.

Opposition backbencher David Feeney was then referred to the High Court to test his eligibility, because he cannot find the paperwork to show he renounced British citizenship.

Mr Shorten said it was regrettable the prime minister missed the opportunity to fix the problem once and for all.

"When they had a chance to refer their own MPs and Labor MPs, they voted against resolving the issue," he said.

"I don't think Malcolm Turnbull should have a leave pass. I am happy, collectively, to have a complete solution. But unlike Mr Turnbull, I don't think there is one rule for Labor and he gives himself a leave pass."