In a letter sent Wednesday to the Senate Foreign Relations committee, which begins confirmation hearings for Trump attorney and bankruptcy expert David Friedman on Thursday, the former ambassadors said that Friedman has staked out “extreme, radical positions” and has derided the two-state solution as an “illusory” fix for a non-existent problem.

The letter urged the committee to “satisfy itself that Mr. Friedman has the balance and the temperament required to represent the United States as ambassador to Israel.”

The letter was signed by Thomas Pickering, William Harrop, Edward Walker, Daniel Kurtzer and James Cunningham, who said in the letter that they “care deeply about Israel: an American ally, a stronghold of democracy in the Middle East and homeland for the Jewish people.” It was posted on Twitter by a reporter for the Israeli daily Haaretz.

Full text of letter by five former U.S. ambassadors to Israel urging Senate not to confirm David Friedman https://t.co/Ag3IaeLLoGpic.twitter.com/vianqXIdQ6

— Amir Tibon (@amirtibon) February 16, 2017

“The American ambassador must be dedicated to advancing our country’s longstanding bipartisan goals in the region: strengthening the security of the United States and our ally Israel, and advancing the prospects for peace between Israel and its neighbors, in particular the Palestinians. If Israel is to carry on as a democratic, Jewish nation, respected internationally, we see no alternative to a two-state solution,” they wrote.

The letter noted that Friedman rejects a two-state solution and notes that he has been “active in supporting and financing the settler movement.”

Friedman has come under fire for derogatory statements he has made against liberal Jews, including calling supporters of J Street, the liberal Jewish Middle East policy group, “kapos.” Kapos are the Jewish prisoners who were forced to work for the Nazis in the concentration and death camps.

In a June op-ed on the website of Israel National News, also known as Arutz-7, a right-wing media outlet, Friedman wrote of J Street supporters: “They are far worse than kapos – Jews who turned in their fellow Jews in the Nazi death camps. The kapos faced extraordinary cruelty and who knows what any of us would have done under those circumstances to save a loved one? But J Street? They are just smug advocates of Israel’s destruction delivered from the comfort of their secure American sofas – it’s hard to imagine anyone worse.”

The New York Times reported Tuesday that Friedman will apologize for the statements during his hearing.

Friedman, who owns an apartment in Jerusalem’s Talbiya neighborhood, speaks Hebrew and serves as president of American Friends of Bet El Institutions, was tapped in December as the U.S. ambassador to Israel.

Several liberal Jewish organizations and their supporters are protesting the nomination.

The groups organized three separate letters this week to the Senate Foreign Relations Committee: one each from over 600 rabbis and cantors, from Holocaust survivors and from Holocaust scholars, protesting the nomination and focusing on Friedman’s use of the term kapo.

Friedman’s supporters include Christians United for Israel, which on Wednesday ran a full-page ad in the Capitol Hill daily, The Hill, in support of his confirmation, and the Orthodox Union, which sent a letter of support to the Senate committee.