Senator Bernie Sanders on Wednesday endorsed Vermont State Senate President Pro Tempore Becca Balint for Vermont’s lone Congressional seat, according to a Balint campaign statement.

“We need leaders who have the courage to challenge the status quo,” Sanders said. “Becca has that courage.” Sanders added that Balint will “combat the existential threat of climate change.”

Balint’s chief competition in the August 9 Democratic primary is Lt. Gov. Molly Gray, who has stronger support from more centrist Democrats. The winner will face the winner of the GOP primary – either Anya Tynio, Ericka Redic, or Liam Madden.

Sanders served in that seat from 1990 to 2006, before being elected to the United States Senate. His endorsement adds to a growing list of progressive endorsements for Balint’s campaign, which in recent weeks secured the support of 350.org founder and Bill McKibben of Ripton, former Green Mountain Power CEO Mary Powell, the Professional Firefighters of Vermont, The American Federation of Teachers union, the Vermont Building Trades Council, and over 60 Vermont elected officials, including Sen. Kesha Ram Hinsdale, who withdrew from the Congressional race and then endorsed Balint.

Balint has also been endorsed by Rep. Pramila Jayapal, Chair of the Congressional progressive Caucus, Rep. Jamie Raskin, Rep. Mark Pocan, Rep. David Ciciline and Rep. Mark Takano.

Gray has strong endorsement backing from unions and seasoned Vermont Democrats. The American Federation of Government Employees (AFGE) is the fifth major union to endorse Gray’s candidacy, following the NAGE-SEIU, the Vermont State Employees’ Union, the International Association of Sheet Metal, Air, Rail, and Transportation Workers (SMART) and The North Atlantic States Regional Council of Carpenters (NASRCC). Gray also has the support of former Vermont governors Madeleine Kunin and Howard Dean.