sydney citizenship crisis rob australian prime minister malcolm turnbull one-seat majority claim another politician senate president wednesday say resign confirm dual national stephen parry leader upper house member turnbull liberal party say submit resignation thursday tell along australian citizenship also hold british citizenship descent parry father bear britain move australia boy 1951 automatically give parry citizenship descent constitution politician must hold australian citizenship eligible elect national parliament wish successor best trust continue reform commence parry say statement parry resignation follow last week high court rule deputy prime minister barnaby joyce ineligible sit parliament hold dual australia-new zealand citizenship elect rule mean government lose one-seat majority low house must rely independents political survival joyce since relinquish new zealand citizenship re-contest seat dec. by-election joyce one group lawmakers know citizenship seven whose eligibility sit parliament throw doubt recent months find dual citizens high court last friday also rule four politicians ineligible sit parliament due dual citizenships turnbull control senate parry departure change dynamics upper house seat assign party alternatives incumbent resign turnbull flag potential change constitution note half australia population 24 million either bear overseas parent bear overseas national referendum would need change constitution australian citizenship crisis claim another lawmaker