A Facebook Inc executive said in an internal memo in 2016 that the social media company needed to pursue adding users above all else, prompting disavowals from the executive and Facebook CEO Mark Zuckerberg.

Zuckerberg will instead send his Chief Technology Officer Mike Schroepfer or Chief Product Officer Chris Cox to appear before parliament's Digital, Culture, Media and Sport committee.

Facebook is taking new measures to curb the spread of fake news by focusing on the "worst of the worst" offenders.