What is happening

Twelve Democratic senators have filed privileged resolutions that will force the full Senate to vote on whether President Trump has the legal authority to wage war against Iran without congressional approval.

The effort grew on 13 April when six additional senators — Merkley, Gillibrand, Van Hollen, Kelly, Warnock, and Kim — joined the original sponsors Kaine, Booker, Murphy, Schiff, Baldwin, and Duckworth.

Why it matters: The US constitution gives Congress the power to declare war, but presidents have increasingly used executive authority to initiate military action. The Iran conflict, now in its second month, is the most significant test of this tension since the 2001 authorisation that underpinned two decades of operations in the Middle East.

The legal argument

The resolutions invoke Section 5(c) of the War Powers Resolution, which directs the president to withdraw forces from hostilities within 60 days unless Congress authorises the action. Because the resolutions are privileged, any senator can force them to the floor after a 10-day filing period.

The Trump administration argues that Iran posed an “imminent threat” that justified military action without prior congressional approval. The White House has also pointed to ongoing ceasefire talks as evidence that the strategy is working.

What the votes show

The House rejected a similar resolution on 12 April by a vote of 219-212. In the Senate, a previous motion to discharge a war powers resolution from the Foreign Relations Committee failed 47-53 in March, with only Republican Senator Rand Paul voting to advance it.

Supporters argue the pattern shows growing, though still insufficient, bipartisan discomfort with executive war-making. Critics say forcing votes that are likely to fail is political theatre that undermines diplomatic leverage.

What happens next

The Senate vote could come as early as this week. Even if it fails, the margin will signal how much Republican support exists for constraining the president’s war powers as ceasefire negotiations with Iran remain fragile.

The 60-day clock under the War Powers Resolution is ticking. Without congressional authorisation, the administration faces a legal deadline that could force a drawdown of operations — or a constitutional confrontation if it refuses.