Knesset Speaker MK Reuven Rivlin yesterday lambasted President Shimon Peres for suggesting that Israel shouldn't strike Iran's nuclear facilities without the support of the United States.

In a letter to all Likud party members Rivlin wrote, "It is inappropriate for any state institution, however lofty, to clash with the government or appear to be speaking on its behalf."

Rivlin wrote that while no one disputes the right of anyone to express an opinion on current affairs, the duty to govern, decide and navigate Israel safely to the shore belongs first and foremost to the government.

"The Knesset is the only state institution that authorizes the government to rule and exercise its powers. Only the Knesset may appoint the government or challenge its actions through a no-confidence motion," Rivlin wrote in the letter.

The letter was a response to remarks by Peres in an interview to Channel 2 television last week criticizing a possible Israeli attack on Iranian nuclear installations that was not coordinated with the United States.

"It's clear to us that we can't do it alone," Peres said in the interview. "We can only delay [Iran's progress]. Thus it's clear to us that we need to go together with America. There are questions of cooperation and of timetables, but as severe as the danger is at least this time we're not alone."

In an interview to Channel 10 the same day Peres indirectly criticized Prime Minister Benjamin Netanyahu, who has said in the past that Israel's first Prime Minister, David Ben-Gurion, would have gone ahead with an attack even if Washington opposed it.

Peres, who was Ben-Gurion's aide, said Ben-Gurion "prevented war and withdrew from Sinai. He wanted to open the Straits of Tiran by force in 1955, but the cabinet decided against it."

Peres' statements evoked unprecedentedly harsh criticism from Netanyahu's aides.

"Peres forgot the role of a president in the State of Israel," one aide was quoted as saying. The aide said Peres erred in believing the 1993 Oslo Accords would usher in a new Middle East.