Key members of Congress are demanding a swift vote on a war powers resolution that would restrain Donald Trump’s military attack on Iran unless the administration wins their approval for what they warn is a potentially illegal campaign that risks pulling the United States into a deeper Middle East conflict.

Both the House and Senate, where the president’s Republican Party has a slim majority, had already drafted such resolutions long before the strikes Saturday. Now they are ready to plunge into a rare war powers debate next week that will serve as a referendum on Trump’s decision to go it alone on military action without formal authorization from Congress.

“Has President Trump learned nothing from decades of U.S. meddling in Iran and forever wars in the Middle East?” said Sen. Tim Kaine, D-Va., a leader in the bipartisan effort. He said the strikes on Iran were “a colossal mistake.”