Liberal member for Bennelong John Alexander has announced his resignation from Parliament after confirming he holds British citizenship.
He announced that he'll stand again for parliament in an upcoming by-election, after renouncing his UK citizenship.
Earlier this week, Mr Alexander, sought advice on whether he is a UK citizen through his father Gilbert Alexander who was born in England in 1907 and arrived in Australia in 1911.
He will be the second member of the House of Representatives forced to resign because of their dual citizenship.
Barnaby Joyce is facing a by-election in New England, after discovering he was a New Zealand citizen, because of his father's birth.