When an unprecedented committee of lawmakers from around the world investigating online disinformation campaigns first tried to meet with Facebook CEO Mark Zuckerberg in November, the company said he was unable to be in London for the hearing.

Now they're planning to invite him to a location a bit closer to Silicon Valley: Ottawa, Canada.

The lawmakers, who held their inaugural hearing in Britain's Parliament, hail from the U.K., Canada, Brazil, Latvia, Argentina, Ireland, Singapore, France and Belgium. They have repeatedly asked Facebook CEO Mark Zuckerberg to appear before the panel, known as the International Grand Committee on Disinformation and 'Fake News.'

Get Breaking News Delivered to Your Inbox

For the London hearing, Facebook sent Richard Allan, the company's vice president for public policy, who sat next to an empty chair reserved for Zuckerberg. Right from the start, Allan faced a series of fiery exchanges with lawmakers bewildered by Zuckerberg's absence and angered by incidents involving Facebook in their countries.

The upcoming hearing on May 28 will focus on "holding digital platforms to account... foreign influence in our democracies, and data as a human right," according to a press release.

"With several countries, including Canada, holding elections this year it is vital that we continue collaborating to protect our democracies from the global threats of foreign influence and disinformation on digital platforms," said Bob Zimmer, Chair of Canada's Standing Committee on Access to Information, Privacy and Ethics in a press release. "This meeting will also provide us with the opportunity to hear from these platforms about what they are doing to protect our citizens from the threats of manipulation that we know are active online."

Zimmer said in an email to CBS News that the committee will once again invite Zuckerberg, as well as other leaders "from the big platforms."