San Francisco CNN Business  — 

Four workers who were recently fired from Google are planning to file unfair labor practice charges against the company with the National Labor Relations Board.

The workers will ask the NLRB to conduct an investigation into Google. The filing is expected to be made later this week, according to a representative for the former employees.

The fired workers, Laurence Berland, Paul Duke, Rebecca Rivers, and Sophie Waldman, told CNN Business they believe they were fired from Google (GOOG) for speaking out against the company over its practices, such as having controversial government contracts. They said they engaged in legally protected labor organizing and that they’re making the charges because they want to ensure their firings don’t scare current Google (GOOG) employees from speaking out.

In response to the claims, Google said it prohibits retaliation in the workplace and that the dismissals were for “repeated violations” of its policies. The workers deny wrongdoing.

“We dismissed four individuals who were engaged in intentional and often repeated violations of our longstanding data security policies, including systematically accessing and disseminating other employees’ materials and work,” a Google spokeswoman told CNN Business. “No one has been dismissed for raising concerns or debating the company’s activities.”

The former workers deny wrongdoing. They published a Medium post explaining their plans to file the charges.

Last Monday, Google sent an email to all staff members describing its decision to fire the four employees for allegedly violating its data-security policies. The email described some of the actions allegedly taken by the fired employees, including accessing other employees’ calendars and sharing information about their whereabouts with outside sources. It was sent out on behalf of Google’s Security and Investigations Team.

Google confirmed the contents of the email titled “Securing our data,” which was first obtained and reported by Bloomberg.

In their time with the company, each of the four said they were vocal in advocating against certain decisions or actions taken by Google. They were involved in matters such as signing letters to cancel controversial government contracts, organizing and participating in walkouts and advocating for unionization.

“General organizing is why I was fired,” Duke, who worked at Google for eight years in its New York City office, told CNN Business. “There were organizing lunches in my office that I attended and sometimes ran, I’ve been active in getting workers together in concerted, protected activity.”

Berland spent 11 years at the company based out of its San Francisco office before he was fired.

“I believe we were fired to intimidate all of the workers,” he told CNN Business. “Google is saying ‘We will isolate you, we will punish you and we will fire you.’”

Berland pointed to a recent New York Times article about Google’s decision to hire a firm reportedly known for its anti-union efforts in what he and some others see as an apparent attempt to crack down on worker activism. Google did not immediately respond to a request for comment.

“They made a conscious decision to bust up organizing,” he said. “Management has tried to intimidate us, to harass us, to scare people out of speaking our minds. Googlers are not buying it, they’re not having it, they’re not scared, they’re going to stand up and fight.”

In its response to the New York Times about its decision to hire the company, Chloe Cooper, a Google spokeswoman, said the company engaged “dozens of outside firms to provide us with their advice on a wide range of topics.”

Waldman, who worked for Google for nearly two years in Cambridge,Mass., said she’s filing charges to help protect other Google employees.

“I enjoyed working at Google, I would not object to being able to work there again but mostly we want to make sure employees who are still working there don’t have these same things happen to them,” she told CNN Business.

Rivers, who was at the company for four years and was most recently based in Boulder, Colo., said she was officially terminated for accessing and sharing documents that were subsequently leaked to the press. She said she shared information with other Google employees that was already readily available to all employees and not marked ‘need to know’ or limited to certain employees. She believes she was fired for participating in petitions that questioned certain contracts between Google and government agencies.

“I think they wanted us to shut up,” she told CNN Business.

Google was long seen as the ideal of workplace culture with enviable benefits such as free meals, on-site childcare and an emphasis on transparency. But the company’s reputation is changing as tensions with employees continue to rise and backlash toward its policies grows.

In recent years, Google employees have engaged in protests and organized walkouts over issues such as the company’s handling of sexual harassment allegations against executives, claims of inadequate action on climate change, pursuit of military contracts, and the potential development of a censored search engine service in China.

In November, demonstrators gathered outside Google’s headquarters in San Francisco as part of an employee protest, demanding that Google rehire two employees, Rivers and Berland, who were put on administrative leave.