SAN FRANCISCO (Reuters) - The Communications Workers of America union filed a federal labor charge against Alphabet Inc's GOOGL.O Google on Thursday, accusing the company of unlawfully firing four employees to deter workers from engaging in union activities.

FILE PHOTO: Google site reliability engineer Laurence Berland addresses fellow employees about how the company put him on administrative leave, during a rally near a Google office in San Francisco, California, U.S. November 22, 2019. REUTERS/Paresh Dave

The complaint, seen by Reuters, will trigger a National Labor Relations Board (NLRB) investigation into whether Google violated the four individuals’ right to collectively raise concerns about working conditions.

Google fired the four named employees “to discourage and chill employees from engaging in protected concerted and union activities,” the filing states. “Its actions are the antithesis of the freedoms and transparency it publicly touts.”

Google did not respond to a request for comment on the filing, though it has said the four workers were let go for violating the company’s data-security policies.

Google also last month acknowledged hiring a consultancy known for defeating unionism.

The CWA union, which represents 700,000 North Americans working at AT&T Inc T.N, Walt Disney Co DIS.N and companies in several other industries, has been trying to organize workers at Google, said Laurie Burgess, an attorney at Messing Adam & Jasmine who worked on the NLRB filing.

The union stepped forward to make the charge against the company “because it has been harmed by Google’s actions,” she said.

If at the end of its investigation the NLRB finds Google has a case to answer, the union could seek to reach a settlement or, ultimately appeal to a court.

CWA spokeswoman Beth Allen said its organizing director has been in touch with Google employees for some time to offer assistance.

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“It’s a good partnership we have and through their own organizing if they decide they want to form a union, we’re here to help them,” she said. “We really believe in workers leading their own struggles.”

The four workers, who were fired Nov. 25, “visibly led and participated in” organizing at Google, according to the filing.

“I was fired for organizing my coworkers and advocating for better working conditions for everyone who works at Google (including employees, temps, vendors, and contractors),” one of the workers, Paul Duke, said in a tweet on Wednesday.

He and others in social media posts since their exit have alleged that Google, which has faced a swell of worker activism over the past two years, wanted to demonstrate consequences for speaking out.

Duke and sacked co-workers Laurence Berland and Sophie Waldman publicly signed a petition in August urging Google to reject business from three U.S. immigration agencies that the petition said had mistreated migrants. The fourth fired worker, Rebecca Rivers, had protested Google policies that appeared to undermine its support for people who identify as gay, lesbian or transgender.

When the NLRB finds violations, it typically tries to help accusers and companies reach a settlement.

Google in September announced such a settlement after an employee accused the company of firing him for his conservative political views. Google said it agreed to remind employees that its “policies do not prevent employees from discussing workplace issues.”

The company has long prided itself on listening to employee feedback and even adjusting course on the spot based on ideas at all-staff meetings. But it now serves more than 3 billion consumers and business customers across search, navigation and health technology, and it faces fierce competition in advertising and increased regulatory scrutiny.

The company in the last year has reeled in elements of its unorthodox culture, such as by cutting back on companywide meetings next year, as it deals with its much broader influence.

Workers and investors have been able to exercise limited oversight over Google’s practices because co-founders Larry Page and Sergey Brin control Alphabet’s shareholder voting power.

The co-founders stepped down Tuesday from their executive roles but retain their votes and board seats.