Facebook and Google are set to be grilled Tuesday about white nationalism on their platforms.

Policy executives from the two firms are scheduled to face questions from the House Judiciary Committee during a hearing at 10 a.m. in Washington.

Facebook recently barred white nationalism from its platform, and YouTube is grappling with the issue.

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Facebook and Google are back in Congress this week facing tough questions.

The Democrat-controlled House Judiciary Committee is set to grill executives from Facebook and Google at 10 a.m. on Tuesday about how they police hate speech on their platforms, The Washington Post reports.

The witness list indicates that Facebook's director of public policy, Neil Potts, as well as Google's public policy and government relations counsel, Alexandria Walden, will testify alongside expert witnesses from civil-rights organizations including the Anti-Defamation League. House Democrats told The Post that Tuesday's hearing would be the first of a series on the issue of white nationalism.

Facebook recently barred white nationalism and white separatism from its platform, saying the ideologies could not be "meaningfully separated" from white supremacy and organized hate groups. The far-right figure Faith Goldy fell foul of the ban this week.

Facebook's ban came shortly after the mass murder of Muslim worshipers in two New Zealand mosques, which was streamed live on Facebook.

The Google-owned YouTube is also grappling with the issue of white nationalism. Last week, the video service all but banned the far-right activist Tommy Robinson, whose real name is Stephen Yaxley-Lennon, restricting likes, comments, and suggested videos from his posts.

The tech giants "clearly have been conduits for that kind of hate speech," Democratic Rep. Jerry Nadler, the House Judiciary Committee chair, told The Post.

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The Republican-controlled Senate Judiciary Committee on Wednesday is set to hold an evidence session on allegations of political bias in tech. The hearing, titled "Stifling Free Speech: Technological Censorship and the Public Discourse," will be chaired by Sen. Ted Cruz of Texas.

US President Donald Trump accused Google of anti-conservative bias in August, claiming the company was rigging search results to surface more negative news stories about him. There was no evidence to support his claims.

More recently in March, the president told reporters that social-media companies silenced conservative voices online. "Something's happening with those groups of folks that are running Facebook and Google and Twitter, and I do think we have to get to the bottom of it," he said.