Malcolm Turnbull has accused Labor of pursuing 'the children and grandchildren of Holocaust survivors' amid pressure on Liberal MP Jason Falinski to resign from parliament over claims he's a Polish citizen.
Federal Labor has ramped up its attacks on a Liberal MP it believes is under a citizenship cloud just as Opposition Leader Bill Shorten calls for a sensible bipartisan compromise to end the fiasco.
The opposition took advice from a Polish expert that Liberal MP Jason Faliski remained a Polish citizen by descent because his father entered Australia on a Polish passport.
Immigration consultant Jolanta Wolski told Labor records at the Office of Citizenship in Warsaw show Mr Falinski's father migrated from Poland using a Polish passport, while legal advice from a Krakow-based firm said this should be conclusive proof of citizenship.
But Mr Falinski said Labor is "clutching at straws" in claiming he was a dual citizen, which would force him to step down from parliament.
"Proudly Australian and only Australian," he tweeted.
"Looking forward to another week in parliament passing laws that matter to my community."
Labor MP David Feeney resigned parliament last week after failing to produce paperwork proving he had renounced British citizenship, and the government continued to raise questions about the status of several other opposition members.
Mr Shorten said the ongoing citizenship saga - which started in the middle of last year - had annoyed a lot of Australians and cast the whole parliament in a poor light.
"To make sure that 2018 is a better year for Australian politics than 2017, I think both sides of politics, all sides need to reach sensible compromise," he told reporters in Melbourne on Sunday.
Prime Minister Malcolm Turnbull backed his MP - saying Labor's advice was "based on facts that are wrong" - and indicated the coalition would continue to pursue opposition MPs.
"What Labor is trying to do is they want to pursue the children and grandchildren of Holocaust survivors like Jason Falinski (to) muddy the waters through the vagaries of central European citizenship law," he told ABC TV.
"They have sitting in the parliament right now Susan Lamb, the member for Longman who - on her own legal advice - states that she is a citizen of the United Kingdom."
Mr Falinski's citizenship register lodged with parliament includes legal advice from Australian firm Arnold Bloch Leibler that was not a citizen of the UK, Poland, Russia or Kyrgyzstan.
However, the lawyers also cautioned they could not provide conclusive advice and recommended Mr Falinski also seek an independent opinion from foreign law experts.