MELBOURNE/SYDNEY (Reuters) - Australia will hold a general election on May 21, Prime Minister Scott Morrison said on Sunday, triggering a campaign expected to be fought over cost-of-living pressures, climate change, and questions of character and competence of the major parties.

       Opinion polls show Morrison's conservative coalition trailing the opposition Labor party after nine years in power. Morrison similarly lagged in opinion polls before the previous election in May 2019, but still pulled off a win.

       "There's still a lot of uncertainty ahead, I get it," Morrison told reporters in Canberra. "But this election and this campaign is incredibly important."

       (Reporting by Sonali Paul and John Mair; Editing by Kenneth Maxwell)