WASHINGTON (JTA) — A Jewish candidate for Illinois governor dropped his running mate over a disagreement about the Boycott, Divestment and Sanctions movement against Israel.

Daniel Biss, a state senator, said in a statement Wednesday on his campaign website that he had made a “difficult” decision to part ways with Chicago Alderman Carlos Ramirez-Rosa just a week after announcing their ticket.

Biss said that he had raised BDS in the interview process and understood that Ramirez-Rosa opposed it, but in subsequent discussions it became clear “that Carlos’ position has changed.”

In a statement Wednesday to the Chicago Sun-Times, Ramirez-Rosa suggested that he opposed BDS on the local and state level — he notably voted against it in a council vote in 2015 — but supported it at the federal level.

“The difference of opinion we have on the role the BDS movement plays at the federal level would make it impossible to continue moving forward as a ticket,” Ramirez-Rosa said in the statement.

Biss came under pressure after it was revealed that Ramirez-Rosa, in an interview a year ago prior to the Democratic National Convention, said that “for too long the U.S. government has subsidized the oppression of the Palestinian people.”

Rep. Brad Schneider, D-Ill., a Jewish Chicago-area member of Congress, dropped his endorsement of Biss, who is running in a field of nine for the Democratic nomination for governor.

Ramirez-Rosa is also a member of Democratic Socialists for America, which endorses BDS.

In his statement Biss, a mathematician running as a progressive, cited his Jewish background in explaining his decision.

“Growing up with an Israeli mother, grandparents who survived the Holocaust, and great-grandparents who did not survive, issues related to the safety and security of the Jewish people are deeply personal to me,” Biss said.

“I strongly support a two-state solution,” he continued. “I support Israel’s right to exist, and I support Israel as the homeland of the Jewish people. I also care deeply about justice for Palestinians and believe that a vision for the Middle East must include political and economic freedom for Palestinians. That’s why I oppose the Boycott, Divestment and Sanctions movement, or BDS, as I believe it moves us further away from a peaceful solution.”

Biss earned unusual support for his decision from a former spokesman for Gov. Bruce Rauner, a Republican whom Biss may face in next year’s election.

“Under Governor Rauner’s leadership, Illinois became the first state in America to divest its public pension funds from companies that participate in BDS,” Richard Goldberg said in a statement. “This should always be a bipartisan issue and I applaud Congressman Schneider and Senator Biss for making clear to the far-left that BDS has no place in the Democratic Party.”