The Electoral Commission in Papua New Guinea says it will go to the Supreme Court with its appeal after a lower court ruled that some of the votes from last year's failed elections in the Southern Highlands may remain valid.
The National Court had decided that a regional candidate's votes could be carried over into the fresh polls for which the process of registration is to start next week.
But the Electoral Commission says the ruling is unreasonable and has made the situation more confused.
The head of the Commission, Andrew Trawen, says a Supreme Court hearing has now been scheduled for Monday so that the election timetable can be kept.
Last year's polling in six Southern Highlands electorates was declared null and void because of violence and fraud.