Rep. Pramila Jayapal, the head of the Congressional Progressive Caucus, on Saturday condemned Israel as a racist state, warning activists that there is an organized opposition against progressive critics of Israel’s policy towards the Palestinians.

The sharp criticism from the lawmaker from Washington state marks among the highest-level condemnations of Israel, as several members of her caucus plan to boycott Israel President Isaac Herzog’s address to a joint session of Congress later this week.

Speaking on a panel at Netroots Nation, an annual progressive activist conference in Chicago, Jayapal was addressing pro-Palestinian attendees interrupting the session.