More than 200 Connecticut school bus drivers could walk off the job Monday because they are unvaccinated and do not want to be tested for COVID-19, officials said Friday. With many towns already struggling to fill routes, the walkout could create a difficult start to the school week for parents and students.

Monday is the deadline for vaccinations for school bus drivers - as well as state and school district employees — under an executive order by Gov. Ned Lamont as he seeks to stem the spread of the ongoing coronavirus pandemic.

In a survey of drivers by the Connecticut School Transportation Association, 1,558 drivers from 12 bus companies said that they are currently unvaccinated. Of those, 1,331 said they would agree to weekly testing, which would allow them to continue driving.

But 227 drivers said that they are unvaccinated and would refuse the weekly tests, said Jean Cronin, the chief lobbyist for the transportation association.

The number of unvaccinated drivers is even higher because only 12 of the 67 companies that are represented by the transportation association were surveyed recently due to time constraints. As such, the number of drivers who fail to show up Monday could be higher.

The bus companies, the governor’s office, and the state education department have been working to avoid a major problem Monday. The bus companies, for example, are proposing a 60-day extension of the vaccine mandate to give them more time to comply.

But Max Reiss, Lamont’s chief spokesman, said flatly, “There are no plans for an extension at this time.’'

Instead, the state is making multi-pronged plans ahead of Monday. First, the state police, motor vehicles department, and Department of Children and Families are working on all aspects of background checks, fingerprinting, and training to expedite any school bus driver applications amid a shortage of drivers. Second, officials are talking with the state’s Medicaid transportation contractor to potentially transport special education students in limited instances across the state. The contractor already drives Medicaid patients on a non-emergency basis to doctor’s offices and other sites.

Third, officials are also talking to CT Transit to potentially use buses and drivers on a short-term basis. The service currently operates buses chiefly in Hartford and New Haven counties.

Fourth, the state is reviewing whether bus drivers could cross town lines to help others in the same way that police and firefighters cross borders in mutual aid on a limited basis during emergencies.

“Parents across Connecticut want their kids around as many vaccinated people as possible,’' Reiss said in an interview Friday. “That’s on the ballfield. That’s in the classroom, and that is on the school bus. It is imperative to get as many people vaccinated as possible.’'

He added, “This could be something that persists. It’s probably not a one-day issue.’'

But Cronin noted that there has been no evidence of health difficulties with the drivers or the students since the pandemic started spreading in Connecticut in March 2020. She said that both the drivers and the children wear masks, and the bus windows are open. In addition, she said the students do not come within three feet of the driver except for more than a few second when entering and leaving the bus.

“For a year and a half, our drivers have been driving kids to school — long before there were vaccines,” Cronin said in an interview. “We didn’t have any outbreaks then. What is different now? Everybody was careful. They’ve been sanitizing the buses.”

Lamont and his top deputies are aware of the situation and are trying to reach a resolution.

“I can tell you we’re in active discussions with the bus drivers,” Lamont said at a news conference Thursday. “I can tell you we’ve done everything to accelerate getting additional bus drivers in place.”

While state officials mentioned employing the state’s Medicaid transportation contractor, Cronin said she is uncertain whether the contractor could get the job done.

“They don’t have student endorsements to drive schoolchildren,” Cronin said. “There’s a background check involved. I don’t know if they have the proper licensure to be driving the kids. This is a serious problem.”

In a letter to the state education commissioner, Cronin wrote, “We have a major catastrophe looming on September 27th when the state COVID vaccination mandate will take effect for school bus drivers. The school bus driver shortage will become 10 times worse on that day, and it will be a crisis driven by government.”

She added, “The state of Connecticut has just created the perfect storm for school bus drivers — they have instituted a COVID vaccine mandate on an industry that was already experiencing a severe driver shortage since before the pandemic, where it takes months to train, test and license a driver. And this comes on the heels of a DESPP criminal background check system failure which resulted in the stoppage of school bus driver application processing for nearly two months. There are not enough drivers to cover the daily school runs now, let alone the athletic events. Parents, school boards and superintendents are up in arms. This mandate could not have come at a worse time.”

The potential statewide stoppage for some drivers comes on top of a statewide and nationwide shortage of drivers.

In Bristol, buses have been late all week, causing some parents to be late for their jobs as they waited at the bus stop with their children. Some towns have offered bonuses as high as $4,000 to attract new drivers.

Cronin said she did not have a list of the districts that could be hit hardest on Monday morning. But the towns with the highest percentages of vaccinated residents would likely have the least problems because many of the drivers work close to home.

“Some of the smaller towns in eastern Connecticut could be problematic,’' Cronin said. “The percentage of the unvaccinated that the state has around the state mirrors our drivers.”

Christopher Keating can be reached at ckeating@courant.com