Rep. Mark Pocan (D., Wis.) has been identified as the anonymous member of Congress who reserved official Capitol Hill space for an anti-Israel forum that is being organized by several organizations that support boycotts of the Jewish state, according to congressional sources who spoke to the Washington Free Beacon.

News of the June 8 anti-Israel event, which was first disclosed earlier this week by the Free Beacon, sparked outrage on Capitol Hill and initiated a search to identify the anonymous member of Congress sponsoring the event.

The event, which sources confirmed to the Free Beacon is being sponsored by Pocan, is being organized by anti-Israel advocacy groups that have supported Israel boycotts and have been cited for distributing propaganda slandering the Jewish state.

Pocan, a supporter of the liberal Middle East advocacy group J Street, has come under fire in the past for meeting with convicted terrorist associated with the Popular Front for the Liberation of Palestine, a terror organization.

Since the Free Beacon first reported on the event—which many have described as a propaganda effort meant to defame the Jewish state—pressure has been mounting for the anonymous congressman behind the event to step forward.

Pocan's communications director, David Kolovson, did not respond to multiple Free Beacon requests for comment on the matter.

Rep. Peter Roskam (R., Ill.), co-chair of the House Republican Israel Caucus, told the Free Beacon on Wednesday that the lawmaker sponsoring the event should publicly step forward and explain his or her support for such a forum.

"It's completely unacceptable to use the resources of the House of Representatives to help promote the hateful, malevolent BDS [Boycott, Divestment, and Sanctions] campaign," Roskam said. "If a member of Congress wishes to sponsor an event like this, he or she should step forward and tell us why."

The event, "50 Years of Israeli Military Occupation & Life for Palestinian Children," is scheduled to be held June 8 in room 122 of Capitol Hill's Cannon House Office Building, according to an invitation viewed by the Free Beacon.

One senior congressional source familiar with the situation said that Pocan should explain why he is backing the event.

"If true, Congressman Pocan should be ashamed of himself. This is the type of event you'd expect to take place in backrooms at the United Nations, but not in the halls of the United States Congress," the source said. "The hosts of this forum have only one goal: to disseminate virulently anti-Israel propaganda. Congressman Pocan should stop hiding behind a cloak of anonymity, take responsibility for facilitating this event, and, ideally, cancel it."

Groups involved in organizing the event include several advocacy organizations known for their criticism of the Israel Defense Forces, or IDF.

They include the Defense for Children International-Palestine and American Friends Service Committee, which operate an affiliated advocacy group dedicated to accusing the IDF of various crimes against humanity.

These organizations have been cited by pro-Israel organizations and watchdog groups for their promotion of anti-Israel propaganda and false information about the IDF.

Speakers scheduled to attend the event include: Omar Shakir, the Israel and Palestinian director for Human Rights Watch, which routinely criticizes Israel; Brad Parker, the staff attorney and international advocacy officer for Defense for Children International-Palestine, a group that backs Israel boycotts; Nadia Ben-Youssef, director of the Adalah Justice Project, which has accused Israel of "genocide"; and Yazan Meqbil, a Leonard Education Scholar and student at Goshen College.