WASHINGTON – War against Iraq is likely, said a senator exploring U.S. options, and other lawmakers joined him Sunday in pressing the Bush administration to make the case to Congress before any attack.

Sen. Joseph Biden, D-Del., led hearings last week that highlighted both the gravity of the threat posed by Iraqi President Saddam Hussein and the difficulty of replacing him with stable leadership.

“I believe there probably will be a war with Iraq,” said Biden, chairman of the Senate Foreign Relations Committee. “The only question is, is it alone, is it with others, and how long and how costly will it be?”

Similar sentiment was ex-pressed by other lawmakers appearing on the Sunday talk shows. Like Biden, they said the administration must do far more to sell Americans, allies and Iraq’s neighbors on the need for force.

They also said Bush must seek congressional approval if he decides on war and heal splits among his own advisers over how best to meet his goal of replacing Saddam.

Administration officials were absent from the airwaves, letting lawmakers drive the debate.

Democratic Sen. Carl Levin of Michigan, chairman of the Armed Services Committee, said Saddam is not likely to launch an attack with biological or chemical weapons unless he is provoked by a U.S. move against him.

“Does he love himself more than he hates us?” he asked on CBS’ Face the Nation. “And I think the answer is probably yes.

“And if that’s true, then it would be unlikely that he would initiate an attack with a weapon of mass destruction because it would be certain that he would be destroyed in response.”

But Biden said divining the Iraqi leader’s plans “is like reading the entrails of goats.” What matters is his capacity to unleash the weapons, whatever his intentions, Biden said on NBC’s Meet the Press.

Senate Majority Leader Tom Daschle said Congress must weigh in before America goes to war. “I don’t think the president has the authority to launch a full-force effort” without congressional approval, said Daschle, D-S.D.

“We all support strongly a regime change,” Daschle said on ABC’s This Week. “But I think we have to get our ducks in order. Do we have the support of our allies? Do we have an appropriate plan?”

The administration has invited Iraqi opposition groups to Wash-ington, possibly this month, to explore what they might be able to do to unseat Saddam. So far, they have not been considered an effective force.

Ahmed Chalabi, head of a London-based umbrella organization representing the fractious opposition figures, said thousands of lightly armed Iraqis in the north, south and Baghdad want to move against Saddam but need training and equipment.

Congress authorized Bush in the fall to use all necessary force against nations or groups that aided the Sept. 11 hijackers or harbored such terrorists.