President Obama is expected to send Congress an authorization for the use of military force to fight the Islamic State group on Wednesday, multiple sources told Fox News.

Lawmakers from both sides of the aisle have pushed for Congress to weigh in and believe the administration is operating outside the Constitutional boundaries of executive power.

The resolution could include possible limitations for ground troops, a time frame and the geographical footprint in which the U.S. operates.

Obama so far has relied on congressional authorizations that former President George W. Bush used to justify military action after 9/11. Critics say the White House's use of these authorizations to fight IS is a legal stretch at best. The president earlier insisted he had the legal authority to deploy 2,763 U.S. troops in Iraq to train and assist Iraqi security forces, and conduct ongoing airstrikes against targets in Iraq and Syria. More recently, the president has said he wants a new authorization, but has not released details.

A congressional official said the president will ask for a three-year authorization so the next president will have to seek renewed authority to fight IS. The official said Obama wants to leave open the option to send in combat forces if needed, but is not seeking an authorization that would permit a prolonged U.S. troop presence on the ground. The White House request also would not restrict the fight to certain geographic locations, but would limit the U.S. to fighting IS militants or any future group that they become, the official said.

One congressional aide said Democrats will not rubber-stamp the White House version, but will seek to rewrite it to include bipartisan views. Another congressional staffer said the debate in Congress will not necessarily flow along party lines because conservative Republicans and liberal Democrats, for instance, have disagreed about two major sticking points: deploying U.S. combat troops and restricting the geographical area served by the new authorization. The second staffer said a final authorization will depend on the language decided on regarding these two issues.

The congressional official and staffers spoke on condition of anonymity because they were not authorized to discuss the ongoing negotiations with the White House.

Generally, conservatives want Congress to approve broad authorities for the president to fight IS with no limits on ground troops or geography. They say banning U.S. combat troops or restricting the fight to Iraq and Syria emboldens the militants, who would not have to worry about attacks from U.S. ground forces and could seek safe haven outside those two nations.
Sen. Orrin Hatch, R-Utah, said the new authorization should be flexible enough so it can be used not only against IS, but also against whatever form the group takes in the future, as well as any groups that associate with or support it materially.

He said he disagreed with those who want to prohibit the use of ground forces or set an expiration date for the authorization.

"These are restrictions that the Islamic State could use to its advantage," Hatch said. "If we are telling the Islamic State upfront that we will not use ground forces, will they not tailor their strategy around that fact? If we advertise when the authorization expires at an arbitrary date ... will they not hunker down and wait for that date?"

Other lawmakers want the new war powers to be narrowly defined to something that gives the president the authority to train and equip local forces and conduct airstrikes, but not launch a combat mission on the ground.

"I've been clear in opposition to boots on the ground, but I'd like to see what they propose and hear them out," said Sen. Brian Schatz, D-Hawaii. "It's traditional and expected for an administration to articulate their strategy to the Congress, so we want to give them a chance to do so."

According to the congressional schedule, Democrats and Republicans may not see the authorization until April.

In December, Secretary of State John Kerry offered Congress a preview of what the White House would want in an authorization measure. But it's not clear if any of the provisions Kerry mentioned to lawmakers still reflects the administration's thinking. Kerry said at the time that Congress should not limit U.S. military action to Iraq and Syria or prevent the president from deploying ground troops if he later deems them necessary. Kerry also said that while the administration does not seek an open-ended authorization, it wants it to include a provision for it to be extended.

The Associated Press contributed to this report