sydney several lawmakers file family history document australia parliament meet government deadline tuesday try prove citizenship stem crisis far claim nine mps cost government majority australia 116-year-old constitution ban dual citizens hold national office high court adopt strict interpretation october country half population either bear overseas parent crisis may yet plunge prime minister malcolm turnbull liberal-national coalition minority rule lose another lawmaker crucial by-election set dec. 19. rule center-right pair lose one-seat lower-house majority high court find deputy prime minister barnaby joyce new zealander therefore ineligible office since rescind new zealand citizenship regain seat parliament another member since quit place many dozen face referral court deadline disclose birthplace parent grandparents pass tuesday disclosures show nearly every lawmaker least one foreign parent grandparent provide citizenship record date back 19th century others give detail document prompt call high court consider case grey areas doubt mp christopher pyne say perth radio station 6pr add parliament would decide thursday case send court one opposition labor party member already tell parliament remain unclear whether british home office could find paperwork prove renounce citizenship decade ago labor argue seven government lawmakers file unconvincing incomplete disclosures government raise doubt four opposition mps cloud another independent lawmaker although joyce easily regain seat by-election saturday crisis still government precariously cling power already dent ability pursue political agenda lose by-election sydney dec. 19 court oust another lower-house mp would force depend handful independent lawmakers retain power pass laws australia mps rush disclose parentage amid citizenship crisis