The UK Parliamentary committee dealing with technology is fed up with Facebook’s lack of answers on data privacy. In a letter to the company today, the chairman of the Digital, Culture, Media and Sport Committee more or less demanded that Facebook CEO Mark Zuckerberg show up later this month for testimony. If he didn’t, the chairman wrote, the committee would force him to appear the next time he entered the country.

Facebook initially declined to provide Zuckerberg for questioning when the committee asked back in March, shortly after the Cambridge Analytica scandal became public. Instead, they provided the committee with Mike Schroepfer, Facebook’s chief technical officer, while Zuckerberg went to testify before the US Congress.

The committee was unhappy with how this played out. “The committee feels that the evidence lacked many of the important details that we needed,” chairman Damian Collins writes. He says that Schroepfer failed to answer nearly 40 questions during his appearance. “This is especially disappointing to the committee considering that in his testimony to Congress Mark Zuckerberg also failed to give convincing answers to some questions.” In his case, it was more than 40 questions, and Congress has not yet heard back.

Zuckerberg faces much tougher questions from the UK

Zuckerberg may have wanted to avoid the committee, at least in part, because of how much savvier it is. While the US Congress peppered him with often inane questions — Senator Orrin Hatch, who has seemingly never used the internet, asked how Facebook made money — the UK committee contains members focused on these kinds of issues and is better equipped to dive into such a broad and complex topic.

In his letter, Collins includes 39 questions that Facebook is supposed to follow up on from Schroepfer’s appearance. Just looking at the list indicates how much smarter its line of questioning is. Questions include: “What is the percentage of sites on the internet on which Facebook tracks users?,” “What is the legal situation regarding Facebook storing non-Facebook users’ data?,” and “Do you know how many developers were using and selling data on to third parties?”

The committee requests answers to those questions by May 11th and asks that Zuckerberg appear on May 24th. He is already scheduled to meet with EU Parliament members around the same time.