Twitter does not operate on the basis of "political ideology", chief executive Jack Dorsey said Wednesday, rejecting claims of bias against conservatives.
The Senate Intelligence Committee has been looking into efforts to influence U.S. public opinion for more than a year, after United States intelligence agencies concluded that Kremlin-backed entities sought to boost Republican President Donald Trump's chances of winning the White House in 2016.
Google says Walker will still submit testimony and brief members on the subject of the hearing, which is foreign influence operations and their use of social media platforms. "We acknowledge the real-world negative consequences of what happened, and we take full responsibility to fix it".
Social media stocks fell after his remarks, with Twitter down 5.7 percent and Facebook around 1.8 percent lower.
Prior to the hearing, President Donald Trump in an interview with the Daily Caller accused social media companies of interfering in the USA mid-term elections in November, without appearing to offer any evidence.
Moscow denies involvement, and Trump - backed by some of his fellow Republicans in Congress - has repeatedly dismissed investigations of the issue as a partisan witch hunt or hoax. Only after CNN highlighted several tweets that clearly violated Twitter's TOS did the social media platform suspend Jones - and only for one week.
The statement from Dorsey released by a House panel covered questions about foreign influence operations on social media as well as accusations of political bias.
Dorsey will follow the Senate hearing with another hearing that could be politically more contentious - an appearance before the House Energy and Commerce Committee that will specifically address Twitter's "algorithms and content moderation".
To kick off his opening statement, Dorsey picked up his phone and said he would be tweeting out his prepared testimony. Some Republicans, including President Trump, have pushed the idea ahead of the elections that Twitter is "shadow banning" some in the GOP because of the ways search results have appeared.
Google said Walker will be on Capitol Hill on Wednesday, adding that company officials first informed the Senate committee that Walker would be Google's representative in July.