The Iran war is close to the 60-day mark — making congressional Republicans anxious enough to consider subjecting President Donald Trump’s powers to significant public debate.

The conflict will hit that critical milestone on Friday. But it’s already triggering a shift on Capitol Hill among Republicans who’ve grown weary of lawmakers taking a back seat to the executive branch. Some of them are actively discussing whether to authorize the war, saying it’s a weighty constitutional matter that requires Congress to hold a War Powers Act debate.

“It’s a big deal. … There are a number of us having discussions about what that day means, what our response should be. It’s important to me that Congress realizes their responsibility, and so I’ll be actively engaged in making sure we do that,” Sen. John Curtis, R-Utah, told Semafor.

Republicans won’t suddenly start backing Democratic measures to cease hostilities. But they do believe the legislative branch can’t keep standing by while the Trump administration deploys thousands of US troops to the Middle East for a war with no clear endgame.

“At some point, people cross some sort of threshold and start to be very uncomfortable with it. I don’t know exactly where that is, but I am sensing restlessness among many of my colleagues,” said another GOP senator familiar with intraparty dynamics.

There’s more evidence of that restlessness: Four Republican senators introduced a bill on Tuesday to cut tariffs and duties on Moroccan fertilizer imports as fertilizer prices rise because of the closure of the Strait of Hormuz. Many Republicans have accepted reassurances from the administration that Trump won’t send ground troops, and the GOP Congress writ large is reluctant to get directly involved in the war.

That dynamic may change after Friday.

“The 60-days [mark] is very important to me. The War Powers Act makes clear that at the 60-day point the Congress needs to authorize any further military action,” Sen. Susan Collins, R-Maine, told Semafor. “Sixty days is a trigger that requires Congress to act.”

There are several potential ways for the Trump administration to stave off Republican interest in invoking the War Powers Act’s 60-day deadline to seek congressional authorization, including commencing with a 30-day withdrawal period that would effectively buy the administration until June. Officials also could argue they don’t need to comply with the letter of the law.

And the administration could also contend that the ceasefire with Iran shouldn’t count towards the 60-day clock.

“We haven’t been doing combat over the last two weeks. I think it merits good discussion,” Rep. Don Bacon, R-Neb., said of military authorization. “In the end, I want us to finish the job.”

Sen. Lisa Murkowski, R-Alaska, who is among the senators contemplating a war authorization, said: “If they need an extension for 30 days, come to us. But you’ve got to talk to us.” She warned that if that doesn’t happen, “you may see a change in the situation” in Congress.

Both parties say they expect engagement from Secretary of State Marco Rubio by the end of the week; Rubio quickly notified Congress in early March that the conflict had started.

Sen. Josh Hawley, R-Mo., said Rubio’s “been pretty careful to comply with the statute. My hope is they’ll notify us that they’re drawing down offensive operations.”

“The secretary of state, national security adviser, archivist, and viceroy of Venezuela owes us some engagement on this point, and as a former senator — more than anyone — he’s the one I look to to do that,” said Sen. Chris Coons, D-Del.

A White House official told Semafor that “the administration is in active conversations with the Hill on this topic,” and warned lawmakers against trying to “score political points.”

“Trump has been transparent with the Hill since before Operation Epic Fury began,” White House spokesperson Anna Kelly said in a statement, pointing to “over 30 bipartisan briefings.”