Just a couple of days after HBO announced several major additions to “White House Plumbers,” the cast has grown again. Nelson Ascencio, Gary Cole, Toby Huss, Zoe Levin, John Carroll Lynch, Zak Orth, Tony Plana and Tre Ryder have joined the upcoming political series, currently in production, Variety has learned exclusively.

“White House Plumbers” is based on the book “Integrity: Good People, Bad Choices, and Life Lessons from the White House” by Egil “Bud” Krogh and Matthew Krogh, as well as public records. It follows how Watergate masterminds E. Howard Hunt (Woody Harrelson) and G. Gordon Liddy (Justin Theroux) accidentally toppled the Nixon presidency that they had been trying to protect.

Levin will play Lisa Hunt, E. Howard Hunt’s “bright and outspoken” eldest daughter who struggles with her mental health and embraces the counterculture, which puts her at odds with her “image-conscious” father. Levin is represented by Anonymous Content, ICM and Felker Toczek Suddleson Abramson.

Plana portrays Eugenio “Muscolito” Martinez, described as a “hardened but melancholy” CIA commando who walks away from a failing marriage to help the Plumbers destroy the Democrats. He is repped by A3 Artists Agency.

Orth is Alfred Baldwin, a former FBI agent who answers a want-ad in a trade magazine to operate surveillance equipment, and becomes the Plumbers’ eyes and ears. He is repped by the Gersh Agency.

Ascencio is Virgilio “Villo” Gonzalez, being called a “hapless” Miami-based CIA-trained locksmith who “never seems to have the right set of tools.” Ascencio is represented by Hanns Wolters International Inc. and Entertainment Lab.

Ryder will play David Hunt, the Hunts’ young son who finds his innocence destroyed by the events of Watergate. Ryder is represented by UTA.

Cole will portray Mark Felt, the “incorruptible” deputy director of the FBI. Cole is represented by the Gersh Agency and Envoy Entertainment.

Huss is James McCord, the “socially awkward” head of security for the Committee to Re-Elect the President, and the Plumbers’ electronics expert. Huss is repped by Artists First and APA.

And finally, Lynch is John Mitchell, Nixon’s “formidable and corrupt” former Attorney General who is now the head of Nixon’s re-election campaign. He is repped by Suskin Management and SRDA Law.

These new eight performers join previously announced cast members Lena Headey, Domhnall Gleeson, Kiernan Shipka, Ike Barinholtz, Yul Vazquez, David Krumholtz, Rich Sommer, Kim Coates and Liam James for the five-episode series.

Alex Gregory and Peter Huyck created the series and will executive produce alongside David Mandel, who executive produces and directs all five episodes; Harrelson; Theroux; Ruben Fleischer and David Bernad for The District; Paul Lee, Nne Ebong and Mark Roybal for wiip; Len Amato for Crash & Salvage; Frank Rich and Gregg Fienberg.

“White House Plumbers” is a co-production between HBO and wiip.