The by-election that will define Dutton’s opposition

<p>The announcement that former Liberal minister Alan Tudge will resign from the parliament marks the end of a controversial political career, but it's also throwing open new challenges for the party, and opposition leader Peter Dutton.</p><p>Speculation is swirling about who will be selected to run for Tudge’s seat in Melbourne at the upcoming by-election, and while the pressure is on for the Liberal party to pick a woman, factional infighting means nothing is guaranteed.</p><p>So, can the Liberals retain the seat of Aston, which it barely clung on to at the last election? Or...