Israel's civil defenses are not ready to protect the population in a missile war, an opposition lawmaker said on Monday, fueling debate about the feasibility of an attack on Iran's nuclear program.Almost one in four Israelis lack access to bomb shelters, whether communal or reinforced rooms in private homes, said MK Ze'ev Bielski (Kadima), chairman of a parliamentary panel on home defense preparations."Are we prepared for a war? No," he told Reuters. "Things are moving too slowly and we are wasting very precious time."Such shelters could be vital if Israel were to attack Iran's nuclear facilities and Tehran struck back, either directly or through its allies on Israel's borders.Israel says 100,000 rockets and missiles are pointed at it, many of these held by Syria, Lebanon's Hezbollah and Hamas, although they may decide to sit out any war between Israel and Iran.The Civil Defense Ministry, which was set up after Israel suffered thousands of rocket strikes in the 2006 Lebanon war, confirmed Bielski's data while seeking to play down his alarm."Our position remains that if everyone does what they are expected to do during an emergency, the situation will be tenable," one ministry official said.This appeared to reinforce remarks in November by Defense Minister Ehud Barak that, should Iran retaliate for an attack with missile salvoes against Israel, it could inflict fewer than 500 fatalities "if everyone stays in their homes".The discrepancy between the vulnerability of Israel's home front and the relatively low casualties forecast by Prime Minister Binyamin Netanyahu's conservative government has several roots.Bielski, a member of the centrist opposition party Kadima, said Israel's advanced missile interceptors and its regular civil defense drills for emergencies stood it in good stead.But he said: "Even if the number of dead is 500, we need to do a lot more in order to stem that. Any number is too many for us."A new report by the Washington-based Center for Strategic and International Studies said Iran's ballistic missiles would be "lucky" to hit within a 1-2 km range of their targets in Israel. But it noted that Israel is 92 percent urbanized -- making even random strikes potentially devastating.