Washington (CNN) Six months after U.S. military action began against ISIS, the White House is poised to send Capitol Hill this week language to formally authorize the mission. But it's far from certain if the measure can pass Congress, which is deeply divided on the issue.

The proposal from the Obama administration, which is expected on the Hill on Tuesday or Wednesday, would approve continued military operations against the terror group in the Mideast, but request a three-year mission so that the next president would have to come back to Congress for new approval, according to a congressional source familiar with the discussions.

The White House will also call for restrictions on American combat troops on the ground, but is also likely to allow some exceptions -- such as for search and rescue missions, multiple congressional sources said.

What is the AUMF? Should Obama bomb in Syria without Congress' okay?

What is the AUMF? Should Obama bomb in Syria without Congress' okay? 01:58

What is the AUMF? Should Obama bomb in Syria without Congress' okay?

The biggest flashpoint in the debate over this authorization will be on the question of ground troops. Many Democrats are wary of opening the door to another ground way in the Middle East while many Republicans don't want to rule out those forces if they are needed to defeat ISIS.

"That's the rub here," said Sen. Robert Menendez, D-New Jersey, the top Democrat on the Foreign Relations Committee. "To try to find an AUMF that can have bipartisan support, that can be narrow enough that's it's not an open-ended check -- a prolonged engagement -- and open enough that it can meet the challenge of fighting ISIL."

When the mission first began in August, the White House insisted President Barack Obama already had the legal authority without congressional action.

But lawmakers in both parties demanded that Congress have a say in debating and approving the mission. The White House eventually relented but, with the fall midterm elections looming and Democrats up against the political wall, Obama officials decided to wait until the new Congress was sworn in.

Sen. Tim Kaine, D-Virginia, is an Obama ally but was outspoken early on the need for Congress to debate and authorize the mission against ISIS, and has been openly frustrated about the White House dragging its feet.

"I'll tell you what offends me about this. We've already lost American service members lives in this operation and we've done it without Congress being willing to do the job of having a vote," Kaine told CNN Sunday on "State of the Union."

"If we're going to ask people to risk their lives, then Congress ought to do our job and put our thumb print on this mission and say, it is in the national interest," he said.

Sen. Bob Corker of Tennessee, the Republican chair of the Senate Foreign Relations Committee, plans rigorous hearings on the plan at which the administration can provide greater clarity on the U.S. strategy regarding ISIS, particularly in Syria, according to an aide. He credited the White House for reaching out to lawmakers ahead of sending their proposal.

"There have been serious consultations and there will be more serious consultations," Corker said.

The new White House proposal will also address the 2002 authorization for the war in Iraq. The discussions are still underway, but one congressional source tells CNN it will either call for repealing it immediately or call for it to expire when Congress passes this new "ISIL-specific" authorization.

Some congressional Democrats who have urged a vote on the effort to fight ISIS also want the administration to agree to roll back the 2001 authorization that Congress passed after the 9/11 attacks. The President has repeatedly said that measure is what gave him the authority back in the summer to begin airstrikes.

Rep. Adam Schiff, the top Democrat on the House Intelligence Committee, told CNN he is pushing to phase out the 2001 authorization as part of this ISIS targeted measure, saying if Congress writes a new bill but allows that one to remain in place the vote on Capitol Hill "is fairly meaningless because future president could simply fall back on the old one."

Regardless of what language the White House sends, an open question is how Congress will bridge the wide gap between hawks and non-hawks on the many issues involved here: whether to restrict the use of ground troops, whether to include a sunset or time limit for the authorization and whether to include geographical restrictions.

"You have one set of people like Sen. [John] McCain who want to grant the administration a virtual blank check as far as I can tell, and then you've got folks who learned from the mistakes of the Iraq war and want to limit the authority. That's just going to be a difficult balance," Rep. Chris Van Hollen told CNN.

The White House and Capitol Hill are still discussing the proposal but members of both parties agree that whatever the administration sends will just be the start of the debate and will be altered after committees weigh in.

Passage of the authorization is far from a sure thing, according to a Senate Democratic aide involved in the process who asked not to be identified in order to discuss candidly prospects for the measure. The aide described getting it to a final vote will be "a very heavy lift. I think it's a long and windy path to passage, if it's possible at all."

House Speaker John Boehner has repeatedly called on the President to help convince members of his own party, many of whom are war weary, to help get the votes to pass a new authorization.

While the foreign relations committees in the House and Senate have jurisdiction over the bill, the armed services committees are also expected to weigh in and hold hearings.

The Senate Democratic aide predicted a final measure would not be voted on before Memorial Day at the earliest.