RAMALLAH, West Bank, 23 April 2003 — The United States and European Union have weighed in behind Palestinian prime minister-designate Mahmoud Abbas in his leadership battle with President Yasser Arafat, senior officials said yesterday.

Arafat, 73, shouted at Miguel Moratinos, the EU’s Middle East peace envoy, and slammed down the phone when he telephoned on Sunday to hammer home an uncompromising message, senior Palestinian officials said.

With a self-imposed deadline for agreement on a Cabinet due to expire tomorrow, Moratinos told Arafat the EU would accept no one but Abbas, also known as Abu Mazen, as prime minister, the officials said. They said the EU envoy telephoned again on Monday. Hanging in the balance are Arafat’s decades-old domination of Palestinian politics and a US-backed peace “road map” that envisions an end to two-and-a-half years of Palestinian-Israeli conflict and creation of a Palestinian state by 2005.

Yesterday, Abbas said he would no longer discuss the formation of a new government with Arafat. “Things have broken down between me and Arafat. I will not come back,” Abbas was quoted as saying by one mediator close to efforts to jump-start talks between the two leaders which stalled late Saturday with Abbas walking out and threatening to quit.

Washington has made its presentation of the peace package conditional on the installation of a new Palestinian government that it hopes will pursue democratic reforms. But Arafat has balked at Abbas’ Cabinet roster and attempts to wrest from him control of Palestinian security forces that under the peace plan are to rein in those attacking Israelis in an uprising for an independent state.

White House spokesman Ari Fleischer said: “It’s important for the future of the Palestinian people that reforms move forward.”

British Prime Minister Tony Blair, a leading campaigner for the road map and backer of Abbas, phoned Arafat for “an exchange of views” on forming the Cabinet, Blair’s office said.