Raleigh, N.C. — Pressure is growing on former Democratic presidential candidate John Edwards to speak out about rumors of an extramarital affair that resulted in a child.

Allegations surfaced late last year that Edwards, a Chapel Hill lawyer and former U.S. senator, had an affair with a videographer for his campaign, that she become pregnant and had a child and that a campaign worker stepped in to claim paternity.

The story first reported by the National Enquirer has been kept alive for months through online blogs, and some observers said it could determine whether Edwards speaks at the Democratic National Convention in Denver in three weeks.

Edwards' long-time associates and former campaign staffers couldn't be reached for comment Thursday, and many Democratic officials declined to discuss the allegations. But they privately are urging him to address the issue to put the rumors to rest.

"Hiding and ducking media interviews that's potentially this explosive won't work," former Democratic consultant Joe Sinsheimer said. "It's not that complicated a question, and if the National Enquirer is lying, he needs to tell us they're lying and he needs to basically threaten them with legal action because that's what a world-class trial lawyer would do in this situation."

Sinsheimer said Edwards' refusal to fight the love-child allegations moved the story from the tabloid pages to the front pages of mainstream newspapers.

"The question of whether it's true or not is now a major news issue," said Phil Meyer, a professor emeritus at the University of North Carolina's School of Journalism.

Meyer said he covered President John F. Kennedy as a young reporter, and he noted the rules the media uses in its coverage of politicians has changed in the last 50 years.

"There were all kinds of rumors about (Kennedy's) dalliances that we didn't even bother to follow up on because we figured that was a politician's private life," he said. "There is no privacy anymore."

The Democratic National Committee said the speaker line-up for the upcoming convention hasn't been set yet. A cloud of suspicion over Edwards' head doesn't help his chances to make the final list, Sinsheimer said.

"You can't walk into a room with 2,000 political reporters and have these questions unanswered. It would be an embarrassment for him and his family, and it would be an embarrassment to (presumed Democratic nominee Barack) Obama," Sinsheimer said. "If Sen. Edwards wants other people to defend him, he's going to have to start defending himself."