Honda Motor Company, the world's largest maker of internal combustion engines, has confirmed plans to shut down its only car assembly plant in the United Kingdom by 2022, and some employees say Brexit is to blame.

The closure of the car assembly plant at Swindon operated by Honda of the UK Manufacturing Ltd. (HUM) will see more than 3,500 employees lose their jobs and will affect at least four times that number in the supply chain dependent jobs at the plant.

The plant builds 160,000 Honda Civic compact cars and CR-V compact crossover SUVs a year. Swindon accounts for more than 10 percent of Britain's total annual output of 1.52 million cars.

Although Honda has refused to detail the exact reasons for its decision to close the plant, the tormenting issue of Brexit is believed to be at the top of the list. A number of Swindon employees made known to British media their belief that Brexit is the main cause of the plant's shutdown and their impending unemployment.

An employee who has worked at Swindon for 24 years blamed Brexit for Honda's sudden decision to mothball Swindon. He said he had voted to remain in the European Union during the referendum but 55 percent of Swindon's voters elected to leave.

Honda, however, has been having it rough in Europe over the past few years. Demand for diesel-engine cars is way down while tougher EU emissions regulations for new motor vehicles have cut car sales and slowing down the release of newer models.

Then, of course, there's Brexit. Honda refuses to comment on the role Brexit played, if any, in its decision. Honda said it won't comment on the "speculation."

"We take our responsibilities to our associates very seriously and will always communicate any significant news with them first," said Honda in a statement.

Last month, Honda said it will shut down Swindon for six days in April to help counter any border disruption from Brexit. It was also preparing to front-load some production at the plant to ship overseas or build up inventories.

Honda workers are "angry, dismayed and worried" at the decision to shut down Swindon, said Alan Tomala, the regional officer for the Unite the Union trade union and a former employee at the plant.

"If the speculation is to be confirmed, 3,500 jobs are at risk," said Tomala. "If closure is confirmed, it will rip the heart out of this area."

This article was originally published in IBTimes US.