According to The Washington Post, Apple and TikTok each have said “no” to requests to testify at a March congressional hearing that would have probed their relationships with China.

Republican Sen. Josh Hawley (Mo.), one of TikTok’s leading critics, had invited the two tech firms to appear at a March 4 session. Both previously had declined to testify at a hearing last year on the same issue.

The Republican senator criticized Apple at 2019 hearing last year for storing Chinese users’ data locally in accordance with government rules. The move threatens Apple customers’ security given Beijing’s broad surveillance powers, Hawley said then, even though Apple stresses it has not built backdoors into its products.