Facebook CEO Mark Zuckerberg will not appear before an "international grand committee" of at least five governments investigating disinformation and election meddling, according to a letter from Facebook obtained by CBS News. The hearing is scheduled for Nov. 27.

Zuckerberg initially turned down an invitation by Damian Collins, a member of British Parliament, and Bob Zimmer, a Canadian lawmaker. But he was invited again after Argentina, Australia and Ireland signed on to the joint inquiry.

On Monday, Facebook's Head of Public Policy for the United Kingdom, Rebecca Stimson, declined on Zuckerberg's behalf, writing in the letter that Zuckerberg will be unavailable.

Get Breaking News Delivered to Your Inbox

"Thank you for the invitation to appear before your Grand Committee. As we explained in our letter of November 2nd, Mr. Zuckerberg is not able to be in London on November 27th for your hearing and sends his apologies," Stimson wrote.

Zimmer told CBS News that the international group of politicians intend to respond to the rejection soon. Zimmer is chair of the Canadian Parliament's Standing Committee on Access to Information, Privacy and Ethics.

He noted that Facebook did not address whether Zuckerberg might be available in the future. Facebook did not immediately reply to an email from CBS News seeking clarification on that point.

The letter from Facebook includes a rundown of efforts and studies documenting the company's ongoing push to combat false news and the work done by its election teams to bring transparency to political advertising.

"You may have heard us refer to some of this work already during the many hearings and communications we've had with committees and Governments around the world," Stimson wrote.

Facebook has repeatedly noted in its refusals to send Zuckerberg to Westminster that Zuckerberg has appeared before Congress and the European Union Parliament, saying in a Nov. 2 letter, "It is not possible for Mr. Zuckerberg to be available to all Parliaments."

The grand committee says its five governments represent 170 million Facebook users. It proposed meeting in one location, offering a way for Zuckerberg to address their concerns.

More governments may sign on, according to a spokesperson for the British Parliament's Digital, Culture, Media and Sport Select Committee.

"There is growing interest from other nations to join the committee," the spokesperson said in an email to CBS News. She did not indicate which specific countries are interested. On Monday, the U.K. committee launched a social media campaign aimed at pressuring Zuckerberg to attend.

Five Parliaments from across the world who represent 170 million @facebook users are asking Mark Zuckerberg to give evidence to them. Retweet if you think he should come and answer questions on the 27th of November.https://t.co/div5qN8QDd — Digital, Culture, Media and Sport Committee (@CommonsCMS) November 12, 2018

If Zuckerberg does not appear, Zimmer told CBS he'd recommend that Collins issue a subpoena for the 34-year-old to appear before the "international grand committee" in London. A refusal to comply with a subpoena could ultimately lead to a finding of contempt of Parliament, he said.

The effort to get Zuckerberg to appear before the multi-nation investigation comes after Britain's Information Commissioner released a report on November 5 concluding that "Facebook... failed to keep [users'] personal information secure because it failed to make suitable checks on apps and developers using its platform."

That conclusion mirrors a scathing preliminary report on "disinformation and fake news" written by the U.K. committee in July. It called for increased oversight of social media companies and election campaigns, while highlighting the use of "scraped" Facebook data by companies associated with the successful Brexit campaign and President Donald Trump's 2016 run.