(CNBC) — Facebook refused to entertain the idea of antitrust regulation of during a hearing in the U.K. Tuesday with representatives from nine governments. Canadian representative Charlie Angus concluded the hearing with a fiery exchange with a Facebook vice president, and suggested they get to what he saw as the heart of the issue — Facebook’s dominance in the social media space.

CEO Mark Zuckerberg declined to attend the hearing, despite the representatives’ repeated insistence. Instead, Facebook’s Vice President of Policy Solutions Richard Allan showed up to answer questions next to an empty chair with Zuckerberg’s name on a placard.

“What we’re regulating … are the symptoms,” said Angus, the vice-chair of the House of Commons’ standing committee on access to information, privacy and ethics. “Perhaps the best regulation would be antitrust.”

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