By-elections, appointments and defections

By-elections and appointments

• On 26 February 1904, Norman Cameron (Free Trade) was elected to replace Sir Edward Braddon (Free Trade) as the member for Wilmot.
• On 30 March 1904, William Maloney (Labour) was elected to replace Sir Malcolm McEacharn (Protectionist) as the member for Melbourne. McEacharn's election in 1903 had been declared void.
• On 18 May 1904, John Chanter (Protectionist) was elected to replace Robert Blackwood (Free Trade) as the member for Riverina. Blackwood's election in 1903 had been declared void.
• On 12 October 1906, Isaac Isaacs (Protectionist) resigned as the member for Indi. H. B. Higgins (Protectionist) resigned as the member for Northern Melbourne the following day. Due to the proximity of the election, no by-elections were held.

Defections

• In 1904, Independent MP James Wilkinson (Moreton) joined the Labour Party.
• In 1904, the Free Trade Party under its leader George Reid took office from the Watson Labour Government. Protectionists Senator James Drake (Queensland), James McCay (Corinella), Allan McLean (Gippsland) and Sir George Turner (Balaclava) accepted office under Reid and effectively ended their connection with the Protectionist Party, becoming Free Trade MPs. They were joined by Richard Edwards (Oxley), Senator Simon Fraser (Victoria), Sir Philip Fysh (Denison) and James McColl (Echuca). Around this time the Revenue Tariff Party was dissolved, and its two parliamentarians, Senator Henry Dobson (Tasmania) and William McWilliams(Franklin), also became Free Traders. Protectionists Sir John Forrest (Swan) and Sir John Quick (Bendigo) also dissolved their relationship with Deakin's party, but stopped short of joining the Free Traders. They were the beginning of what became known as the "Corner" group of independent conservative protectionists.
• In 1906, the Free Trade Party was renamed the Anti-Socialist Party.
• In 1906, the Western Australian Party was formed. Sir John Forrest (Swan), formerly a Protectionist, ran as its endorsed candidate, but in reality remained a member of the "Corner" group.
• Anti-Socialist MP Norman Cameron (Wilmot) lost pre-selection and contested the election as an Independent.
• Labour Senator Anderson Dawson (Queensland) initially announced his intention to retire at this election. He ultimately decided to contest it, but as the Labour candidates had already been selected he ran as an Independent.
• Labour MP James Ronald (Southern Melbourne), whose seat was abolished, was unsuccessful seeking pre-selection for Melbourne Ports. He contested the election as an Independent.