Four US senators have said they will not back a short-term government funding bill unless it bars money for the war in Iran, raising the prospect of a shutdown fight when federal funding runs out on 11 December.

Democratic Senators Michael Bennet of Colorado, Tammy Duckworth of Illinois and Chris Van Hollen of Maryland, along with Vermont independent Bernie Sanders, said in a joint statement on Thursday that any continuing resolution “must include language that restricts the Trump Administration from using appropriated funds to continue his war against Iran.”

“The American people do not want more war in the Middle East — but that is what President Trump has given them. Congress cannot allow Trump to continue his conflict — we must force him to end it,” the four senators wrote.

Shutdown deadline on 11 December

Current government funding expires on 11 December, and legislation must be enacted by then to keep the government open. The four senators argue that the deadline gives Congress leverage, because a short-term funding bill needs at least 60 votes to advance in the Senate, while Republicans hold 53 seats for the rest of this year.

They said the midterm election results showed voters want Congress to end what they called the “illegal and disastrous war with Iran.” In their statement they argued the conflict “has driven up the cost of gas, groceries, and fertilizer” at home, and said: “More than 20 American service members have been killed and hundreds more wounded, while achieving none of President Trump’s stated goals and harming civilians across the region.”

Media reports citing Pentagon estimates have put the cost of the war at $47.1 billion as of mid-October. The war began on 28 February, when the United States and Israel struck Iran, and has since spread across the region.

Democrats divided over shutdown risk

Democratic leaders have not yet agreed on whether to risk a shutdown over the issue. Senator Patty Murray of Washington, the leading Democrat on the Senate Appropriations Committee, said on Tuesday that leaders were debating how long the stopgap bill should last and whether to add restrictions on how the administration can spend the money.

“We’re exploring all options at this point,” Murray said, adding that Democrats did not intend to approve the tens of billions of dollars in additional funding the Trump administration requested this summer for the Iran war.

Senator Tim Kaine of Virginia has called for immediate action, saying the funding bill should cut off money for the war “unless the president is able to convince Congress to authorize it,” according to Responsible Statecraft. Other Democrats, including Senator Chris Murphy, have warned that the administration’s Iran plan could escalate the conflict, but have argued Congress could pass a continuing resolution and take up the war funding fight later.

House talks under way

In the House, Democratic leader Hakeem Jeffries said on Thursday that he did not want to get ahead of bipartisan negotiations, but added that Connecticut Democrat Rosa DeLauro, the ranking member on the House Appropriations Committee, was “working through all of our Democratic priorities to see what’s possible in advance of Dec. 11.”

“House Democrats have uniformly opposed providing any additional money to Donald Trump’s war machine,” Jeffries said. “Taxpayer dollars should be spent to make life more affordable for everyday Americans, not to drop bombs overseas in an endless war.”

Any funding bill would also need President Trump’s signature unless Congress could assemble veto-proof majorities in both chambers, which is unlikely with Republicans in charge of the House and Senate. That leaves the 11 December deadline as the first big post-election test of whether Democrats will use their votes in the Senate to force an end to the war, or keep the government funded and fight over the war in the new Congress in January.

Sources: South Dakota Searchlight and Responsible Statecraft