The battle over opening a new oil and gas frontier off Alaska's Arctic coast shifted to a downtown Anchorage meeting room Thursday. There, the Obama administration heard fervent but conflicting opinions about whether it should end its hold on a major drilling project.

The head of the agency that regulates drilling in federal waters hosted the fact-finding forum to help him review this summer's controversial decision to suspend offshore exploration projects in Alaska and the Lower 48 in the aftermath of the massive Gulf of Mexico oil spill.

Some Alaska politicians criticized the Obama administration's suspension of work on Shell Oil's plans to drill for oil on its leases in the Chukchi and Beaufort seas.

U.S. Sen. Lisa Murkowski, R-Alaska, took the toughest stand. She said the administration has provided no clear justification for suspending Shell's shallow- water drilling project when it also blocked the Lower 48 projects. All of the Lower 48 projects were located in deep water, like the well that gushed in the Gulf -- but unlike Shell's planned wells.

But some Alaska Native leaders, environmentalists and a former state oil-industry regulator ticked down a long list of reasons why the agency should move cautiously on the Arctic: An oil spill in broken ice could be difficult or even impossible to clean up, hurricane-strength storms strafe the region, the nearest Coast Guard base is nearly 1,000 miles away, and the scarcity of roads and landing strips on the Arctic coast make mobilizing a spill response problematic.

The forum was hosted by Michael Bromwich, a former prosecutor who was recently put in charge of the Bureau of Ocean Energy Management, Regulation and Enforcement. The bureau is in charge of oil and gas leasing in federal waters and used to be known as the Minerals Management Service. It now is being reorganized after rampant criticism of its oversight of offshore oil operators in the Gulf of Mexico.

SIGNIFICANT CONCERNS

Opponents and backers of Shell's drilling plans have been fighting for several years before decision makers within federal agencies as well as in the courts.

Thursday's forum lasted for roughly four hours and concluded with rousing speeches from state and local politicians, including the state's two U.S. senators and village leaders from Barrow and Point Hope.

Bromwich told the crowd of more than 100 that BP's Gulf oil spill raised questions about the oil industry's ability to deal effectively with large oil spills in challenging areas -- whether it's deep waters in the Gulf of Mexico or shallow water in the Arctic.

State officials and Anchorage Mayor Dan Sullivan urged Bromwich to advise the Obama administration to lift its suspension of work on Shell's project.

North Slope Borough Mayor Edward Itta said he is ready to cooperate on a "responsible" drilling program but he worries that agency staff will make the same mistakes that the MMS did.

The agency's decisions favoring offshore leasing in the Arctic were stopped repeatedly in court because the agency did a poor job of analyzing the projects' consequences for the environment and did not listen to the local communities, Itta said.

Point Hope Mayor Caroline Cannon said offshore oil development should be barred forever from the Beaufort, Chukchi and Bering seas.

"We rely on that ocean. It's our garden," she said.

UNCERTAINTY ABOUT DRILLING

Bromwich quizzed oil spill cleanup experts, regulators and other Alaskans about what's needed to prevent a spill catastrophe in the Arctic.

He repeatedly asked oil industry experts on Thursday what lessons they learned from the Gulf spill that can be applied to the Arctic.

Alan Allen, an oil spill consultant who has worked in Alaska and on the Gulf spill, said he can't emphasize enough how important it is for spill responders to learn firsthand about cleaning up a spill by conducting spill tests in Arctic waters.

Right now, it's nearly impossible to get permission to put oil in federal waters to test how to clean it up, according to Alaska spill responders.

Shell officials said they have beefed up their Arctic spill response plans in light of the Gulf spill. They will have a pre-built containment dome to place over their wells and they will have a second drilling ship nearby that can drill a relief well in case of a well blowout.

Shell officials reiterated that they can respond to an oil spill in the Beaufort or Chukchi within an hour.

Bromwich said he is spending 90 percent of his time reviewing the offshore drilling suspensions, but he gave no indication when the Obama administration will revisit its decision involving Shell's work.

Shell's Alaska vice president, Peter Slaiby, said in an interview Thursday that he has been unable to determine what federal regulators still need from his company to allow work on their federal drilling permits to resume.