Rep. Steve Israel announced Friday afternoon that he will not challenge appointed Sen. Kirsten Gillibrand (N.Y.) in the Democratic primary next year after President Barack Obama called him personally in an effort to stave off the intraparty fight.

According to a source close to Israel, the five-term lawmaker was just days away from announcing that he was entering the Senate race. But, the source said, in the interest of party unity Israel agreed to Obama’s request.

Obama’s attempt to avoid what could have been a divisive and nasty fight is one of the most overt political moves of his presidency thus far.

“I spoke with President Obama today. He asked me that I not run for the U.S. Senate this year,— Israel said in a statement. “This is a tough, heartfelt decision for me. I have received encouragement to pursue this fight from all corners of our great state. But in the interest of providing New York and our country with a united front for progressive change, I have decided to continue my efforts in Congress and not pursue a campaign for the U.S. Senate.—

Israel also personally thanked Sen. Charles Schumer (D-N.Y.) “for his friendship and guidance during this process.—

Israel was considered the most formidable of possible Gillibrand primary challengers. She could still face another Member of the New York Congressional delegation in the primary next year, as both Reps. Carolyn Maloney and Carolyn McCarthy have been entertaining the idea of running.

Democratic Senatorial Campaign Committee Chairman Bob Menendez released a statement praising Israel and his decision. He said Gillibrand is doing everything possible to be well-positioned to win in 2010.

“The DSCC looks forward to continuing working with her to make sure she is well-prepared for her race,— Menendez said.