CHEBEAGUE ISLAND, Maine — A plan to reduce post office hours early next year is generating opposition from some residents, and from Maine’s two U.S. representatives.

Chebeague is one of several Maine island communities where the U.S. Postal Service, in an effort to reduce costs, has proposed cutting post office hours from eight hours a day to four or even two, according to U.S. Reps. Chellie Pingree and Mike Michaud.

In a letter to Postmaster General Patrick Donahoe, the two Maine Democrats said they are “very concerned that limiting operating hours to such a level threatens the ability of these islands to continue as full-time communities.”

Besides Chebeague, the lawmakers said post offices on Long and Swans islands, Cranberry Isles, Isleboro and North Haven are at risk.

Tom Rizzo, spokesman for the postal service’s northern New England district, said Monday that a decision is expected by early next year about how many hours the Chebeague Island post office will remain open.

Chebeague’s post office is now open 8 a.m.-4:30 p.m. Monday-Friday, closed for lunch from 1-2 p.m., with the lobby open from 7:30 to 8 p.m. The office is also open 8 a.m.-noon Saturday.

During the summer, when the island population swells to about 2,000 people, “there’s not enough time for the postal person to get the work done,” resident Beverly Johnson said on Monday, adding that she could see cutting back a little during the winter, but that even four hours would not be enough time for the office to be open at this time of year.

Postal Service representatives discussed the issue on the island in October. Residents received a handout at the meeting that said listed the locations of the closest post offices, “as if we could drive to them,” Johnson said. “One was Bailey Island, and one was Cliff Island. And that was silly.”

Resident Bob Earnest said Monday that the Postal Service “seemed to have ignored the fact that there’s a body of water between us and other package resources and mailing resources. … They simply don’t realize what logistical challenges get in the way when you’re on an island. The post office is one of our critical links from a personal standpoint, [and] from a business standpoint.”

Rizzo said the decision to reduce hours stems from a revenue loss triggered by customers switching to other forms of communication, including email and cellphones.

“Our traditional customers have been adapting to changes in technology … and are not using the mail as much as they have in our history,” he explained. “We’ve never seen a decline in use of the mail as we have over the past several years.”

The decline has led to significant revenue reductions, Rizzo said. He noted that the Postal Service had scrapped a plan to close 3,700 post offices around the country, having heard loud public opposition to that idea.

“So we pivoted to this plan, which will not have as much savings,” he said, “but still is a step in the right direction as far as being able to sustain a Postal Service for the future.”

The decline in revenue “has outstripped our ability to reduce … expenses, so this is going to be an ongoing challenge,” Rizzo added.

The letter from Pingree and Michaud asked the Postal Service to grant the island offices part-time status, which is given to rural communities where the nearest post office is 25 miles away or more.

“Setting minimum operating hours of six hours a day, this status addresses the hardships residents in these towns would have to undergo in [making] frequent and far trips to the next post office if their facility were only open a couple of hours a day,” the letter said.

“If hours are cut to the proposed levels, residents of Maine island communities would have to bear these same hardships, or even worse,” the letter continued. “These islands are not connected to land by bridge, and a mile by road is not the same as a mile by water. Island residents don’t have the option of driving to the next post office if they want to mail something in a timely fashion.

To travel to the mainland is often an all-day affair that involves riding on a ferry that may only run a couple of times a day.”

Six hours of post office operation a day, the lawmakers said, is a “bare minimum to keep these islands thriving.”