Complex sentence: He became Premier in 1941 when that year's election failed to return the Liberals with a majority government resulting in a coalition government being formed with the Conservatives in an attempt to block the rise of the socialist Cooperative Commonwealth Federation.
Split into simpler sentences: He became premier following after the 1941 election which failed to return the Liberals with a majority government. The Liberals formed a coalition government with the Conservative Party in an attempt to block the rise of the socialist Cooperative Commonwealth Federation.