WASHINGTON — A formal condemnation of antisemitism that is up for a vote in the House this week has touched off a furious debate between older House Democrats and their young liberal colleagues over whether Representative Ilhan Omar is being singled out for unfair treatment over her statements on Israel.

The resolution, likely to be voted on Thursday, grew out of Ms. Omar's suggestion last week  that pro-Israel activists were pushing “for allegiance to a foreign country” — a remark that infuriated leading Jewish members of the House, who say it played into the anti-Semitic trope of “dual loyalty.”

It comes just weeks after Ms. Omar apologized for tweeting that support for Israel was “all about the Benjamins baby,” a reference to hundred-dollar bills that critics said echoed a common anti-Semitic belief that Jewish money is controlling foreign policy.

But progressives in the House and their allies have rallied to the defense of Ms. Omar, a freshman Democrat from Minnesota and one of the first two Muslim women elected to Congress, who was hailed as a trailblazer. Speaker Nancy Pelosi told top Democrats on Tuesday evening that the resolution would also include language condemning anti-Muslim bias as well — a move advocated by the Congressional Progressive Caucus.

On one side are veteran Democrats like Representatives Eliot L. Engel, Nita M. Lowey and Jerrold Nadler — all of whom lead major House committees and all of whom are Jewish. They spoke over the weekend, and some had talks with Representative Steny H. Hoyer, the majority leader, in a frenzied effort to respond to Ms. Omar. They emerged to push for the resolution.

On the other side are younger members like Representative Alexandria Ocasio-Cortez, Democrat of New York, and liberal groups like Justice Democrats and IfNotNow, a movement of young Jews dedicated to ending the Israeli occupation of the West Bank. They accuse Democratic leaders of singling out a woman of color while letting slide comments from Republicans that they deem racist, anti-Semitic or bigoted, including many from President Trump.

“One of the things that is hurtful about the extent to which reprimand is sought of Ilhan is that no one seeks this level of reprimand when members make statements about Latinx + other communities,” Ms. Ocasio-Cortez wrote on Twitter, mentioning a Republican House member who shouted, “Go back to Puerto Rico” on the House floor.