The boss of a Tesla factory has defended the decision to send managers to the homes of workers on long-term sick leave.

In recent weeks, a director of Tesla’s electric car plant in Germany sent managers to check up on about two dozen employees who have continued to be paid while being on sick leave over the past nine months.

André Thierig, the plant’s manufacturing director, said the home visits were common practice in the industry and that the company simply wanted to “appeal to the employees’ work ethic”.

The move by Elon Musk’s US-headquartered carmaker has sparked outrage at the trade union IG Metall, which represents a proportion of the 12,000 workers at the Berlin-Brandenburg gigafactory.

The union has campaigned against what it has alleged are harsh working conditions with “unreasonably” long hours and a poor health and safety record.

“Employees from almost all areas of the factory have reported an extremely high workload,” said Dirk Schulze, a regional director at the union. “When there are staff shortages, the ill workers are put under pressure and those who remain healthy are overburdened with additional work.

“If the factory’s overseers really want to reduce the level of sickness, they should break this vicious circle.”

Sick leave rates at the factory on the outskirts of Berlin, which the union says operates with a “culture of fear”, have commonly hit 15% or higher.

The union has said that there is a “culture of fear” that has caused stress and sick leave among workers.

However, Thierig said some workers were taking advantage of Germany’s labour protection laws.

He said that among the factory’s 1,500 temporary workers, who operate under similar conditions to full-time employees, the average rate of absence through illness is just 2%.

“In our analyses of attendance at work, some phenomena have become obvious: on Fridays and late shifts, about 5% more employees take sick leave than on other weekdays,” Thierig said. “That is not an indicator of bad working conditions because the working conditions are the same on all working days and across all shifts. It suggests that the German social system is being exploited to some extent.”

The company had identified about 200 members of staff who were still being paid but had not turned up for work at all this year. “They submit a new sicknote from the doctor at least every six weeks,” he said.

Last October, Tesla rejected claims made by IG Metall that health and safety provisions at the factory were not adequate.

The factory, which is in Grünheide, south-east of Berlin, was opened in 2022 and is the electric car manufacturer’s first in Europe.

Musk, the Tesla chief executive, cited Brexit uncertainty as a factor in deciding against building a factory in the UK.

Tesla has been contacted for comment.