(CBS) White House lawyers have told President Bush he would not need congressional approval to attack Saddam Hussein's Iraq, although advisers say political considerations could prompt the president to seek a nod from lawmakers anyway.

Two senior administration officials, speaking on condition of anonymity, said White House counsel Al Gonzales advised Bush earlier this month that the Constitution gives the president authority to wage war without explicit authority from Congress.

"Any decision the president may make on a hypothetical congressional vote will be guided by more than one factor," said White House spokesman Ari Fleischer, who declined to confirm that President Bush had received an opinion from Gonzales on the matter.

"The president will consider a variety of legal, policy and historical issues if a vote were to become a relevant matter. He intends to consult with Congress because Congress has an important role to play."

Despite the go-ahead from his legal advisers, administration officials said the president has not ruled out seeking lawmakers' approval if he decides to attack Iraq.

The officials noted that Mr. Bush's father was told in advance of the 1991 war that he did not need congressional authority to act, but nonetheless sought Congress' blessing for his action.

One of the officials said Gonzales also concluded the current president has authority to act against Saddam under the congressional resolution that authorized his father's actions in the 1991 Gulf War. Saddam has not complied with the terms that ended that war, the official said.

Furthermore, the official said President Bush was told he also could act against Iraq on the strength of the Sept. 14 congressional resolution approving military action against terrorism.

Both of the officials said President Bush has not decided whether to use military force against Saddam.

Still, the existence of a legal opinion - along with earlier reports that the Pentagon is drafting attack plans - reflect the seriousness of preparations within the highest reaches of government to pave the way for war against Iraq in case President Bush does decide on that course of action.

The legal advice became public Sunday as Republicans sounded a mixed message for Bush about whether, when and how to use military action to remove Saddam from power.

The Bush administration's policy is that Saddam is trying to develop weapons of mass destruction and is refusing to allow international inspectors to find and destroy them, as Iraq agreed to do after the 1991 Persian Gulf War.

Rep. Tom DeLay of Texas said Sunday the decision to act is the commander-in-chief's, but he expects President Bush to consult with Congress first.

"The president says he's going to consult with the Congress, and he has. The president has taken the advice of many of us in Congress; he wants input from Congress," DeLay said. "He has said he's going to come to Congress when he decides what needs to be done and when it needs to be done, and I expect him to do that."

While saying President Bush properly "is trying to keep the (anti-Iraq) coalition together," DeLay rejected a suggestion by former Secretary of State James A. Baker III that the president should first get a resolution of support from the U.N. Security Council.

The president answers only to the American people through Congress, DeLay said.

Baker, secretary of state to President Bush's father, wrote in Sunday's New York Times that a Security Council resolution is necessary as political cover for any U.S. military action.

"The only realistic way to effect regime change in Iraq is through the application of military force," Baker wrote.

But he added: "Although the United States could certainly succeed, we should try our best not to have to go it alone, and the president should reject the advice of those who counsel doing so. The costs in all areas will be much greater, as will the political risks."

Baker's proposal for intrusive U.N. inspections as a way to justify military action against Baghdad won swift bipartisan backing from the chairman of the Senate Intelligence Committee, Democratic Sen. Bob Graham of Florida, and Sen. Arlen Specter, a Pennsylvania Republican. Both appeared on CBS' "Face the Nation."

"By going to the United Nations, making the request, even if it results in Iraq stonewalling it, would move us into the moral high ground in appealing to our allies for their collaboration and gaining the support of the world for whatever form of action we end up taking against Iraq," Graham said.

Specter agreed. "Before we use military force, we ought to try all of the alternatives: economic sanctions, diplomacy, inspections."

"The beauty about what former Secretary Baker said is ... that Saddam Hussein has already committed himself to inspections by the United Nations, and he's thumbed his nose at the U.N. So going into the U.N. on that one aspect and saying, 'Provide force to do those inspections,' if he continues to stonewall us, I think, is a very sound idea."

Lawrence Eagleburger, who succeeded Baker in 1992, the final year of former President Bush's administration, is among several old-line Republicans advocating caution.

"I think there are any number of complex questions that simply haven't been examined," Eagleburger said on "CNN Late Edition." "And if it's wimpish to say that ... until we know at least with some confidence that we must act now, then I say we need to be very careful about going forward.

"I'm simply saying I think this is much more complex than (DeLay) and his chest-thumpers think it is."