The colonial political parties of the labour movement which preceded the Australian Labor Party date from 1891.  The first Labour MPs were elected that year to the New South Wales Legislative Assembly (aka “the Bear Pit”), winning 35 of 141 seats.  The first Labour government anywhere in the world was in Queensland in 1899, where the administration of Anderson Dawson held office for 7 days.   Federally, the first Labour Government was in 1904, under Chris Watson, a minority government that lasted just 4 months.  The party adopted the US spelling of “Labor” in 1912, in admiration of the US labor movement.
An American journalist and historian of Australia, C. Hartley Grattan (1902-1980), once wrote this about the Party (cited in Button 2012, page 145 large print edition):

It has struggled with every handicap to which political parties are heir.  It has been burdened with careerists, turncoats, hypocrites, outright scoundrels, stuffy functionaries devoid of sense and imagination, bellowing enemies of critical intelligence, irritatingly self-righteous clowns bent on enforcing suburban points of view, pussy-footers, demagogues, stooges for hostile outside groups and interests, aged and decaying hacks and ordinary blatherskites.  Every political party falls heir to these.  But it has outlived them all and still stands for something:  it stands for a social democratic Australia.”

Reference:
James Button [2012]: Speechless:  A Year in my Father’s Business.  Melbourne, Australia:  Melbourne University Press.
POSTSCRIPT (2013-03-30):  And here is a perceptive analysis of the current situation of the ALP by Guy Rundle, writing for Crikey magazine (HT).    I had not previously viewed the ALP’s Right-wing factions as being the descendants of the Catholic social movement, while the Centre-Left and Left factions may be seen descendants of Protestant Fabians and Marxists.