JERUSALEM — The head of Israel's Labour party on Saturday slammed Prime Minister Benjamin Netanyahu for presenting a potential nuclear Iran as the Jewish state's greatest threat.

"It is a mistake to make the Iranian threat into Israel's central problem," Shelly Yacimovitch said in a televised interview with privately-owned Channel 2.

Yacimovich said that sanctions on Iran should be afforded more time to yield results, and stressed the need to be "fully coordinated" with the United States on the issue.

"A military strike is always the last option," she said.

Yacimovich, whose party is currently in the opposition, will be facing Netanyahu in elections most likely to be held in September.

Netanyahu has repeatedly stated that a nuclear Iran was an existential threat to Israel.

He was recently subject to scathing criticism mouthed by his former internal security chief Yuval Diskin, who called the premier and Defence Minister Ehud Barak "messianic" and accused the two of misleading the Israeli public into believing that if Israel launches an attack against Iran's nuclear facilities, Iran would not have a nuclear bomb.

Israel, widely considered the sole if undeclared nuclear power in the Middle East, believes a nuclear-armed Iran would pose an existential threat to the Jewish state and refuses to rule out a pre-emptive strike in a bid to halt it.

The international community has slapped a series of tough sanctions on Iran over widely-held suspicions it is seeking a militarised nuclear capability -- a charge which Tehran denies.

Israel has expressed doubt the sanctions will work.