House lawmakers voted overwhelmingly on July 25 in favor of a resolution demanding a say before President Barack Obama can send more troops to Iraq.

The 370-40 vote demonstrates growing concern that Congress has abdicated too much power to the executive branch in the decade-old war on terrorism. While non-binding, the vote could make it more difficult for the president to ramp up the fight against Islamist militants by making clear the widespread reluctance to engage the United States in what many lawmakers view as a sectarian civil war.

“The main text of this resolution is simple: The president shall not deploy or maintain United States armed forces in a sustained combat role in Iraq without specific statutory authorization,” said Rep. Walter Jones, R-N.C. “This is a monumental step toward reclaiming our constitutional authority.”

Jones co-sponsored the resolution along with Reps. James McGovern, D-Mass., and Barbara Lee, D-Calif. It would initially have demanded the withdrawal of all US troops not there to protect US diplomats and other personnel but was toned down in negotiations with the Republican leadership.