Israel's outgoing home front defence minister says an attack on Iran would likely trigger a month-long conflict that would leave 500 Israelis dead.
It was reported that the fighting would be "on several fronts", with hundreds of missiles fired at Israeli towns and cities.
Israel's outgoing home front defence minister said that Israel was prepared, though strikes on Iran's nuclear facilities had to be co-ordinated with the US.
The Israeli military is taking steps to prevent Iran developing nuclear weapons. Tehran insists its nuclear programme is entirely peaceful.