Australian opposition leader warns of second election

CANBERRA (Reuters) - Australia faces a possible fourth straight year of political instability after opposition leader Tony Abbott, on track to win power in a September election, threatened a second poll if a hostile upper house rejects his plan to scrap a tax on carbon.

One day after Prime Minister Julia Gillard surprised voters by announcing a September 14 election, Abbott on Thursday promised to scrap a carbon tax if he wins office, but added he would call a second election if a hostile Senate rejected his plans.