sentences:  The incumbent Nationalist Party government won re-election, with Prime Minister Billy Hughes continuing in office.The 1919 election was the first held since the passage of the "Commonwealth Electoral Act 1918", which introduced preferential voting for both houses of parliament – instant-runoff voting for the House of Representatives and preferential block voting for the Senate.It was held several months earlier than constitutionally required, so that the government could capitalise on the popularity of Hughes after his return from the Paris Peace Conference.