The Facebook executives were invited earlier this month to appear before the International Grand Committee on Big Data, Privacy and Democracy in Ottawa on May 28, but neither responded. Zuckerberg also ignored requests to address a Canadian committee looking into and on Facebook.
Not attending the hearing could result in the executives being held in contempt of parliament, but the subpoena can only be enforced if Zuckerberg and Sandberg go to Canada.
Lawmakers from about 210 countries are expected to attend the meeting, which is scheduled to be held in Ottawa on Tuesday.a joint international hearing in London last year to investigate disinformation and election interference.
Facebook told CNN that instead of Zuckerberg and Sandberg, it's sending to the meeting Kevin Chan, its head of public policy for Facebook Canada, and Neil Potts, its director of public policy.
Last year, Zuckerbergfollowing the , in which data from as many as was improperly shared with the political consultancy.
Facebook didn't immediately respond to a request for comment.