The caretaker government in Nauru has instituted a state of emergency, dissolved Parliament and announced new elections for this Saturday.
Saturday's poll is an attempt to overcome a political impasse that has blocked parliamentary activity in the Pacific island republic for months.
The opposition grouping says the state of emergency is a threat to human rights such as freedom of expression, and rights to assembly and association.
In its newsletter, the opposition also queries the one week lead in to an election, saying this is inadequate, especially for new candidates.
The state of emergency is set to stay in place up to 21 days from Friday last week, or until a president is named.