Denver won't have enough cops of its own to police the 2008 Democratic National Convention, so Chief Gerry Whitman has called on suburban police departments to help carry the load.

In a recent letter, Whitman asked various metro area police chiefs to pledge forces for the convention next August, Denver police spokesman Sonny Jackson confirmed Tuesday.

Aurora Police Chief Daniel Oates has responded by pledging 300 officers - 50 percent of his street force - for five days.

"I worked the '92 DNC as a young captain in New York," Oates said. "I know what's involved, and that was pre-9/11. I also believe it will be a tremendous policing experience for my cops."

Oates said his offer depends on Denver's assurance that Aurora will be reimbursed for the "hard dollar costs" of policing the convention and won't be held liable if anything goes wrong.

It was not clear Tuesday whether any other chiefs had gotten back to Whitman on his request for reinforcements.

"Various agencies are evaluating their resources before they get back to us," Jackson said.

Denver police declined to release a copy of the letter or to discuss convention security plans.

"We won't talk a lot about what our resources are," Jackson said. "That's not good, to let the bad guys know."

Security at the convention will be the topic of a congressional committee field hearing Friday in Aurora.

U.S. Rep. Ed Perlmutter and three other members of the House Homeland Security Subcommittee on Intelligence, Information Sharing and Terrorism Risk Assessment will host the hearing from 10 a.m. to noon at Aurora's City Council chambers, 15151 E. Alameda Parkway.

Topics include the need for better intelligence sharing among federal, state and local agencies in preparation for the convention, as well as what suburban police departments plan to do to help Denver police.

"My understanding is the plan all along has been for the metro area to cooperate and provide reinforcement," Perlmutter spokeswoman Leslie Oliver said. "We hope this discussion is a catalyst for long-term security preparedness, beyond the convention."