By Dan Gilgoff and Eric Marrapodi, CNN Belief Blog Co-Editors

(CNN) - High-profile pastor Rick Warren has called off plans for a presidential forum that he said was scheduled to include both major party candidates, but there are conflicting accounts about why the event was canceled.

Warren told the Orange County Register that he was nixing his "civil forum" because of the toxic political climate.

"It would be hypocritical to pretend civility for one evening only to have the name-calling return the next day," Warren told the newspaper in an article published Wednesday.

But sources close to President Barack Obama's and Mitt Romney's political campaigns challenged that explanation, saying the event was canceled because of a lack of interest from the respective campaigns.

"As I understand it, Pastor Warren received tepid responses from both camps well before the supposed 'cancellation,'" said a senior Democratic strategist in contact with the Obama campaign.

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"It appears that the event was canceled because neither the Romney nor Obama campaigns thought it was in their interest to do," the strategist continued, speaking on condition of anonymity to discuss a delicate political matter.

A source close to the Romney campaign said that the former Massachusetts governor hadn't planned on attending Warren's event: “We were never going, ever. We offered to do a video.”

A source close to Warren who worked on the event planning disputed the offer of a video from Romney’s campaign, ”considering the unique live, long-form Q & A format of the civil forum, obviously, video representation would have been impossible and was never discussed.”

The source said, “presumably the individual who responded on behalf of Gov. Romney confused Pastor Warren’s conversations with top campaign officials about that event with the exclusive five-minute plenary video that both he and President Obama provided at the request of Saddleback Church for a Global Health and HIV/AIDS Summit that Rick and Kay Warren co-hosted with several other ministry organizations at Georgetown University on July 25.”

During the 2008 election, Warren played host to both major party candidates at his Saddleback Church in Southern California, in what he called Saddleback Civil Forum on the Presidency.

Warren told the Orange County Register this week that this year's civil forum had been scheduled to take place this week and that there was interest from both campaigns and from the media.

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"[T]he TV networks were eager to cover it again since it garnered one of the largest viewing audiences of that election," Warren said. "I talked with both campaigns about the possibility of doing it again, and they were both favorable to participating."

Warren's spokesman declined an interview request on Thursday, referring reporters to the Orange County Register.

At the 2008 forum, Obama and Republican presidential John McCain fielded questions one at a time from the pastor on Saddleback's stage in front of 5,000 people and a nationally televised audience.

"We’ve got to learn to disagree without demonizing each other, and we need to restore civility in our civil discourse and that’s the goal of the Saddleback Civil Forum,” Warren said in the statement after the event.

This week, Warren seemed to criticize both campaigns.

"The forums are meant to be a place where people of goodwill can seriously disagree on significant issues without being disagreeable or resorting to personal attack and name-calling," he told the Register. "But that is not the climate of today's campaign."

"I've never seen more irresponsible personal attacks, mean-spirited slander and flat-out dishonest attack ads, and I don't expect that tone to change before the election," Warren said.

Warren also said a larger issue cast a shadow over the event: religious freedom.

"There are widespread attempts to redefine the First Amendment to simply mean 'You are free to believe anything at your place of worship but you are not free to practice your conscience elsewhere,' " Warren told the Register, saying he was planning a forum on religious liberty for next month.

Warren used the issue to take special aim at Obama.

When asked by the Register what he thought of the candidates views on religious liberties he said, "President Obama's policies clearly show what he values, and I have told him that I adamantly disagree with those particular policies."

In February, Warren joined a chorus of Catholic leaders who denounced the administration over the implementation of a policy that required health insurers to provide no-cost contraception coverage to employees, even those working for Catholic hospitals and colleges.

"I'm not a Catholic," Warren, a Southern Baptist, wrote on his Twitter feed, "but I stand in 100% solidarity with my brothers & sisters to practice their belief against govt pressure."

Most evangelical and conservative Christians from Protestant backgrounds do not oppose the use of contraceptives, as official Catholic teaching does. The issue for those groups was what they saw as a threat to religious liberty.