The leaders of a prominent pro-Israel super PAC with close ties to the American Israel Public Affairs Committee (AIPAC) have warned Prime Minister Benjamin Netanyahu and his rivals against moving forward with plans to annex Israeli settlements in the West Bank, the Jewish Telegraphic Agency reported today.

Mark Mellman and Ann Lewis, the president and co-chair of the Democratic Majority for Israel PAC, reportedly sent a letter to Netanyahu warning that “such a move would make a two-state solution harder — if not impossible to achieve — and would likely have far-reaching negative consequences for the US-Israel alliance.”

They also sent the letter to Blue and White leader Benny Gantz and Yesh Atid party Chairman Yair Lapid.

Why it matters: Mellman and Lewis founded Democratic Majority for Israel to push back against growing criticism of the close US ally from the left. But their letter to Netanyahu indicates that the super PAC is also taking a stand against President Donald Trump’s proposed peace plan, which gives the green light for Israel to annex Israeli settlements in the West Bank as well as the entire Jordan Valley. Conversely, AIPAC President Betsy Berns Korn praised the Trump plan at the organization’s annual policy conference last month.