Australian Prime Minister Tony Abbott has defended his unpopular government against mounting criticism, saying his administration has made achievements during its first year in power and its performance was more important than appearances.

Public dislike of Abbott has been blamed in part for his conservative coalition's weekend loss in state government elections in Victoria, Australia's second most populous state.

He said on Monday that his government had recently appeared "a bit ragged," but added that more importantly his government "has a very solid year of performance under its belt."

Abbott's government has been trailing the Labor Party opposition in opinion polls since shortly after the 2013 election and is becoming the least popular first-term government Australia has seen in decades.