The U.K. and Canada have convened an “international grand committee” on disinformation and fake news and have called on Facebook chief Mark Zuckerberg to give evidence when the panel meets Nov. 27.

British and Canadian probes into fake news have both previously attempted to get Zuckerberg to appear, without success. In a joint letter to the social media mogul, the two nations’ governments said that they understood “it is not possible to make yourself available to all parliaments” but that international Facebook users deserved “a line of accountability to your organization – directly, via yourself.”

The united stand was taken by the British government’s Digital, Culture, Media and Sport Committee and Canada’s Standing Committee on Access to Information, Privacy and Ethics. They said that other countries are expected to join their collective effort.

The international panel will scrutinize disinformation and governance of the Internet and issue findings later this year. Facebook has already been slapped with a fine in the U.K. for the Cambridge Analytica data breach. Separately, the British government is set to levy a new tax on Facebook and other digital firms on the revenues they generate in Britain.

In their letter to Zuckerberg, U.K. committee chief Damian Collins and his Canadian counterpart, Bob Zimmer, noted that there has never been an international committee hearing of this kind on digital news. “Given your self-declared objective to ‘fix’ Facebook, and to prevent the platform’s malign use in world affairs and democratic process, we would like to give you the chance to appear at this hearing,” they wrote.