Parliament’s digital, culture, media and sport (DCMS) committee asked Zuckerberg a week ago to show up to give oral evidence. In a letter, committee chair Damian Collins said Facebook officials had previously misled the lawmakers about risks in the site’s data-sharing practices, and said it was “now time to hear from a senior Facebook executive with the sufficient authority to give an accurate account of this catastrophic failure of process.”

“Given your commitment at the start of the New Year to ‘fixing’ Facebook, I hope that this representative will be you,” Collins wrote.

However, on Tuesday Facebook told the committee that “Mr Zuckerberg has personally asked one of his deputies to make themselves available to give evidence in person.”

The company said this would either be chief technology officer Mike Schroepfer or chief product officer Chris Cox, either of whom would be “well placed” to answer questions.

The episode suggests Zuckerberg might not show up to testify before Congress, either. The CEO said last week that he was happy to appear in front of U.S. lawmakers if he was “the person at Facebook who will have the most knowledge.”

Senate Judiciary Committee chair Chuck Grassley on Monday became the latest senator to call on Zuckerberg to show up at an April 10 hearing on data privacy.

The Federal Trade Commission (FTC) has also opened an investigation into Facebook and its role in the siphoning of 50 million users’ data by an academic who then sold the information to political consultancy Cambridge Analytica without those users’ knowledge. The news of that probe on Monday helped to drive the company’s valuation down below what it was at the start of the year.