Complex sentence: An open question surrounding first-round victory was resolved by the Electoral Commission on 19 February 2009; it decided that an absolute majority of eligible voters was needed to win in the first round, not just an absolute majority of participating voters.
Split into simpler sentences: An open question surrounding first-round victory was resolved by the Electoral Commission on 19 February 2009. It decided that an absolute majority of eligible voters was needed to win in the first round, not just an absolute majority of participating voters.