Recode has learned that Amazon CEO Jeff Bezos expressed dissatisfaction in recent weeks that company officials weren’t more aggressive in how they pushed back against criticisms of the company that he and other leaders deem inaccurate or misleading. What followed was a series of snarky and aggressive tweets that ended up fueling their own media cycles.

The timing was likely not coincidental. Bezos and other Amazon leaders are on edge as the company is facing the largest union election in its history at its Bessemer, Alabama warehouse. Election results will be tallied early this week, and Amazon officials understand that if a majority of the employee voters vote to unionize, it could set off a chain reaction at other facilities, with the potential to force the e-commerce giant to overhaul how it manages its hundreds of thousands of front-line US workers. There was terror inside the executive ranks of Amazon the last time a union election was held at a US Amazon facility — and that was only a small subset of a warehouse’s workforce, the majority of whom voted against unionization. That vote happened in early 2014, and consisted of just 27 technicians and mechanics at an Amazon warehouse in Delaware. In Alabama, though, the stakes are much higher with nearly 6,000 workers eligible to vote. Bezos knows all of this well.