An Australian MP has become the 10th politician to be unseated from parliament over a dual nationality saga.
Labor MP David Feeney said he would resign after being unable to prove that he had renounced his UK citizenship.
Last year, nine politicians were ousted over concerns they held dual citizenship – although two later returned through by-elections.
Dual nationals are not allowed to stand for parliament in Australia.
Mr Feeney said he thought he had renounced his British citizenship, but he could not find the paperwork despite “extensive searches”.
“I am unable to disprove that I am a dual citizen,” Mr Feeney told reporters on Thursday.
He had found proof that he renounced Irish citizenship, he said.
Mr Feeney said he would not contest the seat again in a by-election.
Deputy Prime Minister Barnaby Joyce was among two MPs who were reinstated to parliament following by-elections in December.