Top Senate Democrat Chuck Schumer has said that the Iran war "must end" and suggested his party's incoming congressional majority could use its control over government funding to push for an end to the conflict.
"This war must end. It must end," Schumer told journalists on Wednesday, later noting that the "power of the purse" is "one of the ways of deterring a president who does war without the consent of the American people."
The US and Israel launched joint strikes on Iran on 28 February, triggering repeated deadly missile exchanges that have disrupted oil shipments through the Strait of Hormuz and pushed up fuel prices.
Democrats have argued that President Donald Trump launched the war without the congressional authorisation they say is required under the US Constitution, which gives Congress the power to declare war.
The House approved war powers resolutions in June and July, while the Senate passed one on its 10th attempt. Republican senators reversed their position the following day after Trump criticised them during a closed-door lunch.
In mid-September, the House passed a third resolution by 220 votes to 204, with seven Republicans joining Democrats. At the time, 19 US service members had been killed and more than 750 wounded, according to figures cited at the time.
The Congressional Budget Office said the war had cost more than $38 billion as of 1 August and projected that inflation would be 0.5 percentage points higher heading into 2027.
A poll in July found that most Americans believed the war was not worth fighting.
The war powers resolutions have struggled to take effect, partly because Trump can veto them. With Democrats set to control both chambers after the midterms, their ability to influence government funding could provide another avenue to challenge the war.
