"If the right people are elected we will be able to continue with raises and benefits at or above our present levels," the insert said. "If others are elected we will not."
The fast food chain's corporate headquarters in Oak Brook, Ill., distanced itself from the action by Canton franchisee Paul Siegfried, saying it was not reflective of the company's position.
Secretary of State Jennifer Brunner, the Democratic elections chief, said she was launching an investigation because the action appeared to violate Ohio election laws.
Allen Schulman, an attorney representing one of the employees, said Friday he had forwarded the paycheck insert to Canton's city law director, citing state and federal laws against corporate advocacy in elections.
"It's no surprise to anyone that Ohio is a battleground state in this election, and for a multinational corporation like McDonald's to threaten employees like this is morally and legally wrong," Schulman said in a statement.
Siegfried issued an apology later Friday, emphasizing the value he places on employees and their freedom of choice in the upcoming election.
"Distributing this communication was an error of judgment on my part," Siegfried said in a statement. "Please know, it was never my intention to offend anyone. For those that I have offended, I sincerely apologize."
The handbill with a simple McDonald's logo at the top recommended votes for Republicans John Kasich for governor, Rob Portman for U.S. Senate, and Jim Renacci for Ohio's 16th congressional district. A Renacci campaign flier was also included.
Shirley Rogers Reece, general manager for the company's Ohio region, said McDonald's had no knowledge that the handbill was being distributed.
"We wholeheartedly respect diverse views and opinions, and our employees' right to vote," she said in a statement. "Our position is that every employee should make his or her own choice."
Shulman told city law director Joe Martuccio the letter was "clearly designed to intimidate, threaten and coerce a captive group of employees to vote for specific candidates at the risk of their jobs, their raises, and their benefits."
In her statement, Reece said that McDonald's did not endorse any of the candidates mentioned in the handbill.
"While clearly this was poor judgment, we don't believe it was intended to offend anyone," Reece said.
Kasich faces Gov. Ted Strickland in Tuesday's election. Portman is running against Lt. Gov. Lee Fisher for the open seat currently held by U.S. Sen. George Voinovich. Renacci is challenging first-term Rep. John Boccieri in one of the most closely watched congressional races in the country. Strickland, Fisher and Boccieri are all Democrats.
Brunner said her office would investigate the letter and hand off findings to the state attorney general.
"Voter intimidation is a form of voter fraud. It is a serious offense requiring a strong response," she said in a statement.
She also issued an overall warning to the state: "The election is just four days away. All involved would be best to play fair, fight hard for what they believe in and work together for all Ohioans and our country in this democratic process not enjoyed in countries elsewhere."