Missouri Rep. John Joseph Rizzo said Friday that he won’t resign despite an admission by two relatives that they provided false addresses in order to vote in his razor-close 2010 primary.

But his opponent in that race, Will Royster, said the admissions show Rizzo should leave office.

On Friday, John and Clara Moretina, Rizzo’s aunt and uncle, pleaded guilty in Jackson County court to voter fraud. The Gladstone residents admitted they illegally claimed a Kansas City address in order to vote in their nephew’s 40th district Democratic primary in August 2010.

Rizzo won that primary election by a single vote. That means two fraudulent votes could have provided his winning margin.

On Friday, though, Rizzo said the guilty pleas by his relatives should not tarnish his victory.

“I’ve been re-elected since then,” Rizzo said. “Hopefully, these guilty pleas will end the talk about an election held almost three years ago.”

Rizzo repeated his assertion that he was unaware of the illegal votes by his aunt and uncle.

“It’s just unfortunate,” he said.

John Moretina, 60, had already pleaded guilty to a federal charge of voter fraud in connection with the 2010 election. He is awaiting his sentence.

Clara Moretina, 61, was not charged in the federal case.

Both were fined $250 on Friday and barred from ever voting again in Missouri.

“Justice was done,” said Jackson County Prosecutor Jean Peters Baker in a statement.

Through their lawyer, the Moretinas declined to comment.

Royster accused Rizzo of lying about his relatives’ votes and called on him to leave office.

“It is no coincidence that the two people closest to John Rizzo are the first to be prosecuted,” he said in an email. “Rizzo should resign or be forcibly removed from office.”

Republicans have used the case to illustrate the need for election reform.