Democratic lawmakers are on the verge of passing a resolution to end President Trump’s war with Iran — with some help from a steadily growing group of Republicans.

In the House and Senate, resolutions under the 1973 War Powers Act this past week saw more members of Trump’s party crossing the aisle to vote in favor of the so-far failed measures, with others voicing their support for a future resolution.

Up until now, House and Senate Republicans have defeated multiple war powers votes brought by their Democratic colleagues since the start of the U.S. campaign in Iran on Feb. 28. But some in the GOP who were initially hesitant to rein in Trump have soured on his administration’s lack of a clear plan for the conflict and skyrocketing fuel costs for their constituents — a byproduct of Tehran’s closure of the Strait of Hormuz.

In the House on Thursday, GOP lawmakers narrowly voted down a resolution that would have directed Trump to remove U.S. armed forces from hostilities against Iran. A tie vote of 212-212 meant the measure failed under chamber rules.

Three Republicans — Reps. Thomas Massie (Ky.), Brian Fitzpatrick (Pa.) and Tom Barrett (Mich.) — crossed the aisle to support the measure. One Democrat, Rep. Jared Golden (Maine), opposed it.

But Golden, a former Marine who served in both Iraq and Afghanistan, has indicated he’ll support the next war powers resolution. He said he only opposed the last measure because it had a withdrawal deadline that had already passed.

“I look forward to voting for a clean, relevant resolution as soon as possible,” Golden said in a statement Wednesday.

And Rep. Frederica Wilson (D-Fla.) could return to Congress after being absent for four weeks and not voting on any issue since April 17. Wilson released a statement Thursday that she recently underwent eye surgery and was unable to fly but plans to be back in Washington, D.C., soon.

With Rep. Tom Kean Jr. (R-N.J.) also absent since March 5 because of a “personal medical issue,” Republicans can’t have more than two defections on an otherwise party-line vote.

In the Senate, meanwhile, a motion to discharge a war powers resolution from the Senate Foreign Relations Committee failed by a vote of 49-50 on Wednesday.

It marked the seventh attempt in the upper chamber to pass such a measure since the war began and the closest it’s come to passing, with Sen. Lisa Murkowski (R-Alaska) voting in favor for the first time.

It also marked the first time the Senate voted to end the war since the expiration of the 60-day window set by the War Powers Act of 1973. The act, designed to limit the president’s authority to wage war abroad without the consent of Congress, requires that the president notify Congress within 48 hours of military action launched in response to an imminent threat. It also bars armed forces from remaining deployed for longer than 60 days without congressional approval — though the president may request a 30-day extension to ensure the safe withdrawal of troops.

The 60-day clock began ticking on March 2, when Trump notified Congress of the use of force against Iran. Democrats argue the clock expired May 1.

Murkowski joined Sens. Susan Collins (R-Maine) and Rand Paul (R-Ky.), along with nearly every Senate Democrat, in voting to advance the measure. Sen. John Fetterman (D-Pa.) was the only member to cross the aisle in the other direction.

The next such vote could swing in the Democrats’ favor should any one of the several Republicans who have voiced concerns about the need for Congress to authorize military action beyond 60 days switch their vote.

“We know what our colleagues are hearing,” Sen. Tim Kaine (D-Va.) said before the Wednesday vote. “We’re starting to hear doubt creep into their words.”

Frustrations with the conflict, which is now estimated to cost $29 billion, were on display earlier last week when Republicans pressed Defense Secretary Pete Hegseth to explain the administration’s strategy in back-to-back House and Senate Appropriations hearings.

“It seems to me that there’s been a different plan, almost daily, with dealing with this problem,” Collins said of U.S. efforts to reopen the Strait of Hormuz, a critical shipping lane closed by Iran for months.

Several GOP senators have suggested Congress should play a larger role if military operations go past the statutory limit but voted no this week: Sens. John Curtis (Utah), Thom Tillis (N.C.), Josh Hawley (Mo.) and Todd Young (Ind.).

Curtis has said he will not support tens of billions of dollars in supplemental funding for the war — a request that has not yet been delivered to Capitol Hill — without an authorization from Congress for the war.

And Tillis told NBC News in late April that it would be “difficult” to get his support to continue the conflict beyond 60 days because he was “not quite clear what the strategic objectives are.”

Hegseth has argued that the war has not, in fact, gone past the 60-day marker, as the clock for the conflict stopped when Trump announced a ceasefire in April.

Both Trump and Secretary of State Marco Rubio have argued the War Powers Act is unconstitutional, potentially previewing the legal fight ahead if Congress does pass a resolution on the Iran war in the coming weeks.