Twelve senators introduced legislation on Thursday that would ban the Donald Trump administration from attacking Iran without congressional approval. The bill, introduced by Sen. Tom Udall, D-N.M., with the support of Minority Whip Dick Durbin, D-Ill., and 2020 presidential candidate Bernie Sanders, I-Vt., boasts the support of one Republican: Sen. Rand Paul of Kentucky.

Why it matters:  The bill, which mirrors legislation Udall first introduced in September, marks the latest salvo in the increasingly partisan battle over the future of US Iran policy. The liberal lobbying group J Street immediately endorsed the legislation, arguing that “the Trump administration’s destructive approach is alienating key US allies and courting disaster.”

The bill is unlikely to gain much bipartisan support, given that Udall and Durbin accused the Trump administration of agitating for war with Iran in a Washington Post op-ed last month. With Democrats in control of the House, however, it could pass at least one chamber of Congress and spark a debate over Iran policy ahead of the 2020 elections.

“While Iran is no innocent actor, the Trump administration’s policies and pronouncements have only increased tensions in the region,” the senators wrote. “Ever since President Trump churlishly withdrew from the Iran nuclear deal, the president has engaged in saber-rattling rhetoric meant to accelerate hostility.”