House Democratic leaders on Wednesday offered a stern warning to Republicans hoping to put hundreds of millions of dollars toward President Trump’s border wall next year: You’re on your own.

“They know that the majority of the Democrats don’t support funding for that wall,” Rep. Linda Sánchez (D-Calif.), vice chairman of the Democratic Caucus, told reporters in the Capitol.

“If they choose to include it, then they are basically saying, ‘We have the votes among the Republican Party to pass this without a single Democratic vote.’ And if they’re not successful, the blame lies squarely at their feet, because they are in the majority.”

Democrats used that leverage in April, when Trump insisted on substantial new border wall funding in a 2017 omnibus bill, only to see it stripped out at the last minute. Democratic leaders are vowing to use that leverage again this summer, as the fight over 2018 border wall spending heats up.

“We intend to exercise it to keep that language out, to keep the money out,” said Rep. Joseph Crowley (D-N.Y.), chairman of the House Democratic Caucus, who characterized the border wall funding as “a gross, negligent waste of taxpayer dollars.”

“I won’t speak on behalf of all the Democratic Caucus … [but] I do think the overwhelming — overwhelming — majority of our membership are not interested in a single penny towards the wall.”

The Democrats’ remarks came a day after the House Appropriations Committee passed a 2018 funding bill governing the Homeland Security Department, which includes almost $1.6 billion to strengthen security at the U.S.-Mexico border. Only $498 million of that targets new wall construction — enough to extend the barrier roughly 28 miles through Texas’s Rio Grande Valley — with the bulk going toward new and secondary border fencing.

But Trump centered his successful campaign on promises to erect an imposing new wall along the entirety of the border — at Mexico’s expense — and after surrendering on the issue in the omnibus debate, he immediately threatened to take a harder line in the coming fight over 2018 funding.

“The reason for the plan negotiated between the Republicans and Democrats is that we need 60 votes in the Senate which are not there!” Trump tweeted three days before he signed the 2017 omnibus into law. “We either elect more Republican Senators in 2018 or change the rules now to 51%.

“Our country needs a good 'shutdown' in September to fix mess!”

It remains unclear whether the Democrats would swallow some new 2018 border security funding if it doesn’t go toward new wall construction, as they did in the omnibus. Meanwhile, they’re leaving little doubt where they stand on the wall itself.

“It’s a medieval solution to a modern-day problem that is destined to fail and it wastes precious resources that we need to conserve,” Sánchez said.

“If they’re going to add poison pills, they can’t be too upset with the result that they aren’t garnering Democratic votes.”