Crawford, Tex. ? White House lawyers have told President Bush he would not need congressional approval to attack Saddam Hussein’s Iraq, sources said Sunday night.

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 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 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.

Furthermore, that official said 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 Bush had 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 way for war against Iraq if Bush so chooses.

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.

Invade right away, after telling Congress, was one course. A second would have Bush wait for a better assessment of the Iraqi president’s danger to American security, then hold off until lawmakers gave their approval.

Some Republicans want Bush to get U.N. authorization before moving, probably after giving Saddam an ultimatum to allow more inspections for weapons of mass destruction, which he would be expected to refuse.

Bush did not expect such divergence among leading Republicans, which broke into the open in recent weeks from lawmakers including Sen. Chuck Hagel of Nebraska, the top Republican on the Senate Foreign Relations Committee, and Rep. Dick Armey of Texas, the House majority leader.

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.