The Abandon Harris movement is throwing its support behind a third-party candidate for the November election, dealing a blow to Vice President Kamala Harris and threatening to siphon away votes in key swing states she’ll need to win in order to secure the White House.

Abandon Harris endorsed Green Party candidate Jill Stein on Monday, criticizing the Biden administration for its response to the war in Israel and its failure to reach a ceasefire deal in Gaza. The endorsement comes on the one-year anniversary of the Hamas attack, which ignited the creation of groups such as Abandon Harris and others that protested the reelection of President Joe Biden or Harris in response to their stance on Israel.