The fight to replace Alan Tudge in the Aston by-election is shaping up as a Melbourne Cup field of candidates.
Labor has announced breast-cancer survivor Mary Doyle will aim to put health care on the national agenda in her bid to win the Victorian seat being vacated by the retiring federal Liberal MP.
Mr Tudge on Friday delivered his resignation letter to Speaker Milton Dick, who is considering a date for the by-election, which is expected to feature candidates from the major parties, Greens and One Nation and possibly an independent.