melbourne australia embattle conservative prime minister malcolm turnbull shake speculation security leadership declare sunday lead coalition government next election 2019. turnbull face horror run recent weeks lose one-seat majority call stepdown christmas say run government party policies would soon convert public support every confidence lead coalition next election 2019 win turnbull tell sky news television confident able see discipline approach teamwork within coalition three australian prime minister oust party since 2010. turnbull confidence bolster stun by-election victory former deputy prime minister barnaby joyce easily cruise victory saturday night huge 65 percent primary vote barnaby kick parliament one month ago hold dual citizenship new zealand status since rescind australia constitution dual citizens ban national parliament barnaby win restore turnbull slim one-seat majority parliament turnbull struggle record low opinion poll claim victory vote confidence performance turnbull sustain attack much year issue include sex marriage scandal-plagued bank sector fail end widespread disquiet within coalition future leader friday conservative deputy premier new south wales state john barilaro call turnbull step christmas gift nation comment come days turnbull force embarrass policy reversal call royal commission country bank financial sector amid mount political pressure turnbull fail stem flow disgruntle voters away conservative coalition far-right party fragility government exacerbate dual citizenship crisis force number lawmakers like barnaby recontest seat one by-elections blue-ribbon conservative electorate bennelong sydney dec. 16 could see turnbull lose majority parliament opposition labor achieve surprise win embattle australian pm say lead government next election