The White House sought authority on Wednesday to expand its military campaign against the Islamic State, against a backdrop of mounting opposition to US foreign policy not just from the Republican opposition but from inside Barack Obama’s own party.

The draft bill seeking three-year authorisation for the use of military force (AUMF) made its way to sceptical lawmakers in a bid to update – for the first time since the 9/11 attacks – a heavily contested legal authority that the administration claims was approved for its recent strikes in Iraq and Syria.

Text of the letter released by the White House confirms a report in the Guardian on Tuesday that the new AUMF does not include geographic limits in the war against Isis and would allow troops to operate on the ground for limited periods of time almost anywhere in the world.

“The authorisation I propose would provide the flexibility to conduct ground combat operations in other, more limited circumstances, such as rescue operations involving US or coalition personnel or the use of special operations forces to take military action against Isil leadership,” Obama writes.

“It would also authorise the use of US forces in situations where ground combat operations are not expected or intended, such as intelligence collection and sharing, missions to enable kinetic strikes, or the provision of operational planning and other forms of advice and assistance to partner forces.”

The White House insists the AUMF does not confer authority for “long-term, large-scale ground combat operations”, but the language has already raised concerns among Democrats that it gives the White House another “blank cheque” for open-ended war wherever it chooses. Some Republicans argue instead that the restriction would tie the hands of the military.

Obama already faces an unusually broad array of opposition to current policies in Iran, Cuba and Ukraine, and he may have to rely on the same coalition of political hawks from both parties to pass the latest legislation opposing him on other fronts.

On Tuesday, the Republican and Democratic leaders of the House armed services committee launched a separate bill that would require the White House to provide arms to Ukraine to help it fight Russia-backed separatists – something Obama has expressed concerns about but the White House insists he is still considering.

Democratic senator Bob Menendez has already joined with Republicans to push another bill that the White House claims will try to derail its talks with Iran over nuclear weapons by authorising new economic sanctions. Menendez is also working with Republicans to frustrate Obama’s diplomatic rapprochement with Cuba.

“While I believe an AUMF against Isil is important, I have concerns that the president’s request does not meet this standard,” House speaker John Boehner wrote in a statement, adding that “rigorous oversight” would begin in the form of hearings.

But more dovish Democrats are equally concerned that the new AUMF may represent a step too far in the opposite direction, potentially granting both Obama and future presidents the same kind of unrestrained cover to wage war last used by George W Bush, after he sought authority based on intelligence that was later found to be false.

“There remain very grave questions that have yet to be resolved,” said senator Richard Blumenthal, after a briefing by White House staff on the AUMF. “I have yet to be convinced. We’re all consulting at this point with each other, generally struggling for a consensus.”

Fears of an overly broad resolution also began to be voiced openly among senior Democrats on Capitol Hill on Tuesday evening, as lawmakers prepared for Wednesday’s release by warning against giving the administration a “blank cheque”.

“This is the rub, this is where it’s going to be very very difficult; you are going to have senators McCain and Graham saying it shouldn’t necessarily be limited to Iraq and Syria,” said Adam Smith, the ranking member of the House armed services committee. “I would support a more limited version and if in a few years from now, new situations emerge Congress can pass it again. I don’t think we should give the executive a blank cheque.”

Smith told the Guardian he believed the proposed three-year limit was a strong sign that the White House was staying closer to proposed language drafted by congressman Adam Schiff, but said Democrats would have significant concerns.

“There is going to be a bunch of Democrats who are going to very very wary of supporting an AUMF after the experience of the 2001 and 2002 AUMFs, so it is going to have to be limited to get enough Democratic support,” Smith added.

Schiff said he backed the decision to seek a fresh AUMF but reiterated concerns that the resolution only repealed the previous 2002 version and not the original passed after 9/11, leaving open the risk of abuse from future occupants of the White House.

“There are some key aspects of the proposal which I believe must be narrowed further – in particular, a new authorisation should also include a sunset of the 2001 AUMF; without one, any sunset of the new authorisation will be ineffectual,” Schiff said. “There are additional concerns over the lack of a geographic limitation and a broad definition of associated forces which will also be the subject of debate.”