Hundreds of Washington Post staffers are on strike Thursday for 24 hours in protest of recently announced staff cuts and frustration over contract negotiations between the company and the union.

More than 750 workers were participating in the Thursday strike, the paper reported. According to a letter to readers posted by The Washington Post Guild, a protest of this size has not been staged at The Post since the 1970s. 

“Taking this historic action is not a decision we came to lightly,” the Guild said in the letter. “We take seriously the impact it will have on the people, issues and communities we cover.”

The Guild posted on social media as the strike officially began, asking readers to send a letter to executives at The Post, including interim chief executive Patty Stonesifer and incoming publisher Will Lewis.

As of Thursday morning, more than 9,100 letters have been sent, according to Action Network, with a goal of sending 12,800.

Why are Washington Post Guild members on strike?

The union, which represents roughly 1,000 employees at the Jeff Bezos-owned newspaper, has yet to arrive at an agreement after 18 months of new contract negotiations with executives. 

Post workers are also dealing with a reduced staffing after executives announced in October that it aims to slash its workforce by 10% through voluntary buyouts in an effort to reduce headcount by 240, according to an article written by the Post at the time. The article said that interim CEO Patty Stonesifer told staff in an email that the Post’s subscription, traffic and advertising projections over the past two years had been “overly optimistic” and that the company is looking for ways “to return our business to a healthier place in the coming year.”

The Guild has asked readers to avoid reading or sharing The Post’s editorial content during the strike, which includes print and online news stories, podcasts, videos, games and recipes.

“On Dec. 7, we ask you to respect our walkout by not crossing the picket line: For 24 hours, please do not engage with any Washington Post content,” the Guild said.

In a statement to CNN, a spokesperson for The Post said that the newspaper will "make sure our readers and customers are as unaffected as possible.”

“The Post’s goal remains the same as it has from the start of our negotiations: to reach an agreement with the Guild that meets the needs of our employees and the needs of our business,” the spokesperson said.