Mofaz, a former army chief, may be lining up a challenge to Olmert
A key defence official has accused one of Israel's deputy prime ministers of threatening to attack Iran in order to boost his own political standing.
On Friday Shaul Mofaz said military strikes to stop Iran developing nuclear weapons looked "unavoidable".
Deputy Defence Minister Matan Vilnai said Mr Mofaz was using the issue to position himself to challenge Prime Minister Ehud Olmert's leadership.
Mr Mofaz's comments were partly blamed for a record oil price surge.
Mr Vilnai told Israel Radio Mr Mofaz's comments were linked to a likely leadership contest in Mr Olmert's Kadima party, if the prime minister is forced to step down over corruption allegations.
Mr Olmert denies taking $500,000 (£250,000) in bribes or illegal campaign donations.
He has not been charged, but says he would resign if indicted.
"Turning one of the most strategic security issues into a political game, using it for the internal purposes of a would-be campaign in Kadima, is something that must not be done," Deputy Defence Minister Matan Vilnai told Israel Radio.
The broadcaster quoted another senior defence official as saying Mr Mofaz's interview "did not reflect policy".
And an unnamed foreign ministry official told AFP news agency: "Mofaz should keep quiet. Everyone in the country understands his motives are election-related, but making statements like this puts Israel in a very awkward position internationally."
An aide to Mr Mofaz told Reuters: "We would like his statements to be taken at face value, and not be given alternative interpretations."
In comments published in Yediot Ahronot newspaper, Mr Mofaz, who is one of three deputy prime ministers and also the transport minister, said Israel would attack Iran "if it continues with its programme for developing nuclear weapons".
Analysts blamed Mr Mofaz's comments in part for a record one-day jump of $11 in oil prices, bringing the cost of crude to a fresh all-time high at $139 a barrel.
Many commentators in the Israeli press have also lashed out at the transport minister.
Yediot Ahronot economic analyst Sever Plotzker asked: "Blathering away about how 'we'll attack and destroy you' does not deter the decision-makers in Tehran, but it does drive the oil markets crazy... And who profits from that? Tehran."
Iran insists that its nuclear programme is for peaceful purposes, but it is defying a demand from the UN Security Council to stop the enrichment of uranium.
Iran's outspoken president, Mahmoud Ahmadinejad, has said the Holocaust of European Jewry is a myth and has called repeatedly for an end to the Israeli state.
The UN Security Council has approved three rounds of sanctions against Iran.