(CNN) The showdown continues between the University of California, Berkeley, and Ann Coulter over whether the conservative firebrand will speak at the famously progressive school.

Citing safety concerns, administrators on Wednesday postponed Coulter's scheduled April 27 appearance, saying it needed more time to find a "suitable venue."

But Coulter was not having it. In a Twitter rampage and a Fox News appearance, she accused the school of canceling the event and vowed to speak as planned. Event co-sponsor Berkeley College Republicans also pushed back, saying Coulter, a "highly sought after speaker," could not change her schedule.

Coulter's threat to speak on April 27 "regardless" of Berkeley's wishes forced the school to act fast and reschedule the appearance for May 2, said Dan Mogulof, assistant vice chancellor for public affairs.

Police have very specific intelligence of threats to Coulter, attendees and protesters, UC Police Dept. Captain Alex Yao told CNN. They said they expect a repeat of violence that pre-empted former Breitbart News editor Milo Yiannopoulos' appearance at the school in February.

Again, it seems Coulter will not play ball.

"I'm speaking at Berkeley on April 27, as I was invited to do and have a contract to do," she said on Twitter after Berkeley announced the May 2 date. "GOOD NEWS FOR CA TAXPAYER! You won't be required to pay $$$$ to compensate me & my crew for rebooked airfare & hotels. I'm speaking on 4/27."

Coulter said the school attached a series of conditions to the April 27 appearance: She had to deliver her speech in the afternoon, only students could attend and the venue would not be announced until close to the event. She said she accepted the terms but the school called off the event anyway.

The school said it was taking extra precautions in light of the Yiannopoulos protests and recent riots in the city, adding that it was "firmly committed" to rescheduling. "Most Mondays and Tuesdays in September during the day should work," the school said.

Friday, Berkeley College Republicans and conservative conference organizer Young America's Foundation -- which had been trying to organize the Coulter event -- rejected the May 2 proposal. They threatened legal action, saying the school's actions violate "fundamental principles of free speech, equal protection and due process."

In a letter from their lawyer, the organizers said the event was intended as a "counterpoint" to a talk by Maria Echaveste, an adviser to US President Bill Clinton.

The organizers said they followed protocol, acceding to the school's "discriminatory" conditions, only to have the event rescheduled to a time when most students would be studying for exams. The May 2 date would "eviscerate" student access to the event, "depriving Berkeley students of a much-needed counterweight" to liberal viewpoints.

"It is ironic that UC Berkeley, known to many as the birthplace of the free speech movement, is now leading the vanguard to silence conservative speech on campus," the letter read. "Surely a public institution of higher learning should be a crucible of challenging ideas and thought, not a kindergarten where wards of the state are fed a steady diet of pasteurized pablum."

The school rejected the allegations said it would discontinue efforts to plan the May 2 event.

In a letter to organizers, Berkeley's counsel said the school had dedicated more resources to facilitating college Republican events this semester than to "any other student group in memory." The letter faulted organizers for failing to notify the school or seek a security review before signing its contract with Coulter.

"We are dismayed that your letter suggests a disregard of the professional judgment of law enforcement regarding security concerns," Chief Counsel Christopher Patti wrote in the letter, "but we stand ready to work with BCR to find a date, time and venue where its rights and campus security can be maximized."