The Nauru MP and former president, Sprent Dabwido, says he suspects the government has intervened to stop local media from running the opposition's campaign advertising.
Nauru's general election is on Saturday, and Mr Dabwido also accused the government of manipulating the police commissioner to prevent the opposition from holding a rally.
He said local media had been running the government's election advertising for weeks, but had yet to broadcast the Opposition's commercial.
"One is ready to go right now, one is almost ready," he said.
"We're willing to pay for that and they said we'll get back to you, we have to talk to higher authorities. There's only four or five more days to go to the election so we're not too hopeful on that now. So there is political interference unfortunately."
Sprent Dabwido said to publicise their campaign, Opposition candidates were circulating brochures in which they're unable to criticise the government for fear of prosecution.
The Nauru government was unavailable for comment.