 The 1978 Constitution of Sri Lanka introduced the proportional representation electoral system for electing members of Parliament.The existing 160 mainly single-member electoral districts were replaced with 22 multi-member electoral districts.Jaffna electoral district was replaced by the Jaffna multi-member electoral district at the 1989 general elections, the first under the PR system, though Jaffna continues to be a polling division of the multi-member electoral district.