Tesla fired several hundred employees this week, even as it tries to increase production, according to a report published Friday.

The Palo Alto maker of luxury electric cars fired an estimated 400 to 700 employees, according to the Mercury News. The newspaper based that figure on estimates given by current and former Tesla workers, most of whom spoke on condition of anonymity. The employees cut included managers, engineers and factory workers, according to the paper.

A Tesla spokesman, while not confirming numbers of people let go, said the company conducts annual performance reviews, rewarding some employees and cutting others.

“As with any company, especially one with over 33,000 employees, performance reviews also occasionally result in employee departures,” the spokesman said.

The automaker is in the midst of an ambitious acceleration of production, with plans to produce half a million cars next year. But that expansion has not gone smoothly. The company reported this month that it built just 260 units of its latest car, the Model 3, during the most recent quarter, far short of its prediction of 1,500 cars in September.

At the same time, Tesla is facing complaints from some factory employees that the company has tried to stifle their efforts to join a union. An administrative law judge with the National Labor Relations Board is scheduled to hold a hearing on the matter on Nov. 14.

According to the Mercury News, some of the employees fired this week believe they were targeted for their pro-union views.

David R. Baker is a San Francisco Chronicle staff writer. Email: dbaker@sfchronicle.com Twitter: @DavidBakerSF