Facebook Inc., Twitter Inc. and Alphabet Inc.’s Google will all send their top lawyers to testify Nov. 1 in front of congressional committees investigating how Russian state actors used social networks and online platforms to interfere in the 2016 U.S. presidential election.

Facebook’s Colin Stretch, Twitter’s Sean Edgett and Google’s Kent Walker will represent their companies, the technology giants said. The three general counsels will face intelligence committees from both the House and Senate that are expected to grill the companies on what they knew about Russian attempts to use their platforms to influence the election, when they knew it, and what they’re doing to prevent it from happening again. The companies have already briefed committee members in closed-door sessions.

The news puts to rest the question of whether top executives such as Facebook’s Mark Zuckerberg or Sheryl Sandberg, Twitter’s Jack Dorsey and Google’s Sundar Pichai would be the ones fielding lawmakers’ inquiries. Sandberg met with members of Congress in private last week and gave an interview on the subject of Russian activity on the social network. Zuckerberg has also spoken to reporters and published blog posts in recent weeks, all part of a broader public relations campaign to push back on the flurry of questions about the company’s role in the presidential elections and democracy in general.

One issue Congress is already moving forward on is transparency in political ads. Republican Senator John McCain joined Democrats Amy Klobuchar and Mark Warner today in announcing a bill that would require online advertisements to disclose the same information about their funders as radio and TV ads.