BATTLE CREEK, MICH. — Five U.S. senators have sent a letter to the Kellogg Co. asking the Battle Creek-based company to “act swiftly to find a fair agreement” to end a strike that has been in place since last October at a cereal plant in Memphis, Tenn. The strike has affected more than 200 employees.

“Many of these hardworking individuals have been employed by Kellogg’s for decades,” wrote senators Sherrod Brown of Ohio, Robert Casey Jr. of Pennsylvania, Cory Booker of New Jersey, Robert Menendez of New Jersey and Jeff Merkley of Oregon in a March 6 letter addressed to John Bryant, president and chief executive officer of Kellogg. “They have made their career working for your company. Yet rather than being rewarded for their hard work and loyalty, they have been forced off the job. Not only are workers without pay, but families are without health insurance, unsure if they can afford their prescriptions or visit a doctor. The result is that these workers, who help prepare the food that others eat each morning, must decide whether they can put food on the table or pay the bills.

“This lockout not only harms the workers, but the entire Memphis community as well. At a time when our nation’s inequality gap continues to grow, replacing good-paying middle-class jobs with lower-wage, casual workers should not be the corporate standard, and it is not keeping with your company’s history of nourishing families ‘so they can flourish and thrive.’

“Kellogg’s workers work hard. They deserve nothing less than fair pay, benefits and full-time hours for their work. We sincerely hope that you will end this lockout and let your employees return to where they want to be: at work.”

The senators are just the latest group to push for an end to the lockout. Other groups that have sent letters to Kellogg in recent months urging an end to the lockout include the National Action Network, the National League Players Association and the Congressional Black Caucus.

Kellogg and the facility’s employees represented by BCTGM Local 252G last fall bargained for a new labor contract at the Memphis plant between September and October before Kellogg on Oct. 16 gave the union an ultimatum to accept the company’s “last/best” offer or be locked out of the Memphis plant.

Kellogg has yet to respond to the latest concerns from the senators, but in a Feb. 28 letter to its Memphis employees the company acknowledged that “four months is long enough.”

“Your frustration and disappointment at the continuation of the current situation in Memphis is evident and understandable,” wrote Marty Carroll, senior vice-president of Kellogg North America supply chain, and Chris Rook, Memphis plant director. “We are frustrated, too. It is deeply concerning to Kellogg that employees who have given so many years of quality service to this company are not currently on the jobs in which you have served us so well. We want nothing more than a resolution to these negotiations so we can all get back to the important work of moving this plant forward, together. You have a choice in this matter, and we hope you choose to return to work.”

But Mr. Carroll and Mr. Rook stressed that Kellogg is facing “significant challenges” in ready-to-eat cereal and the Memphis plant is not set up for long-term success.

“Consumers are engaged in an unconscious migration away from cereal toward other breakfast options,” they wrote. “This should not come as a surprise to you. We have shared this information with you — most recently during the pre-negotiations town hall meetings — and with your union — as the trend has progressed.

“We also have shared with you on several occasions the impact of this trend on our cereal network. In short, pounds are down, costs are up, and we currently have more manufacturing capacity than is necessary to meet the needs of our customers. This is especially true in Memphis, where these very conditions required us to lay off employees last spring.”

Mr. Carroll and Mr. Rook also addressed what they called “inaccuracies,” saying Kellogg is not seeking to replace the locked out workers with part-time, low wage labor, is not insisting that casuals go without benefits, and is not attempting to diminish locked out employees’ seniority.