GENEVA (Reuters) - The head of U.N. refugee agency UNHCR said on Friday he hopes common sense will prevail in Australia's election-season debate about how the country treats asylum seekers. "We are of course very much interested, not in the election itself, but in the debate about asylum policy in Australia," said U.N. High Commissioner for Refugees Antonio Guterres. Opinion polls predict the government of Prime Minister Kevin Rudd's Labor Party will be unseated by the conservative coalition led by Tony Abbot when Australians vote on September 7. In a pitch to voters concerned about immigration, Abbott promised last week to revive tough laws barring thousands of asylum seekers already in Australia from settling there permanently. "The debate about these questions, not only in Australia but in many other parts of the world, is unfortunately not always based only on realities. It's based on perceptions, on prejudice, on other aspects," Guterr