House Freedom Caucus chairman Rep. Mark Meadows (R-NC) told Breitbart News exclusively that the next government spending bill must fund President Donald Trump’s promised border wall, or there will likely be a government shutdown.

In a phone interview on Monday morning, Meadows—the chairman of the most influential group of House conservatives in Congress, the House Freedom Caucus—said that there are enough members in Congress to hold the line against any funding bill that does not explicitly provide for the beginning of construction of President Trump’s border wall. What’s more, Meadows says, his conversations with President Trump indicate that the president is supportive of such efforts and would veto—or refuse to sign—any government funding bill that falls short of the commitments necessary to begin construction on the border wall.

“There is nothing more critical that has to be funded than funding the border wall for two reasons,” Meadows, a key ally of President Trump, said in his phone interview with Breitbart News. “One is it is a commitment that the president made to the American people and one that he intends on keeping, but the second part of that is for our national security we must secure our borders. And the American people will accept no less.”

The current government funding bill runs out at the end of September, and there will be a government shutdown if the Congress does not pass—and President Trump does not sign into law—a new funding bill by the end of the fiscal year. Meadows told Breitbart News there are enough Republicans in Congress who will block any bill that does not fund the wall construction.

Meadows said:

Without a doubt there is enough conservative members who will not support any funding mechanism that does not include border wall funding and it’s also even some who are probably even a little bit less conservative as it relates to immigration because it is the major impediment for really fundamentally getting control of what we do from an immigration standpoint. Until we secure our southern border, there will be no pathway to citizenship for anybody and we can’t revamp our legal immigration process until we’ve secured our southern border. But, yeah, conservatives are definitely going to support the president in demanding that there be funding for the border wall.

Meadows added that he believes President Trump is supportive of these efforts and will not sign any bill that falls short on this count. The White House has not commented on the record when contacted by Breitbart News about this matter.

Meadows went on to say:

My conversations with the president have led me to believe that there is nothing less than a full and total commitment on his part to only sign into law a funding bill that actually allows for us to start construction of a border wall on our southern border. He’s committed to do that. We’re committed to supporting him in that position. And most importantly, the American people are willing to support him in that and believe that it’s a campaign promise that this president is going to fulfill.

Meadows also said he does not believe a bill could pass the House or Senate without border wall funding in it. He is not yet sure whether House or Senate GOP leadership is on board. He continued:

I think that sometimes our leadership has to understand where the American people are, so regardless of where their personal conviction may be on this I think they understand in order to get 218 votes and 60 votes in the Senate it’s going to have to include border wall funding and if not we’re going to be looking at a continuing resolution and finding other ways to do emergency funding for the border wall.

Spokespersons for House Speaker Paul Ryan have not responded to requests for comment on this front from Breitbart News. A spokesperson for Senate Majority Leader Mitch McConnell told Breitbart News that the Senate is focused on passing a repeal and replace of Obamacare and will deal with this problem later.

Meadows said that the Democrats in Congress, in both the House and Senate, would be voting against national security if they oppose efforts to fund President Trump’s border wall. He added:

If we’ve got Democrats, whether they be in the House or the Senate, that are not willing to put our national security as their very top priority and secure our borders, I think it’s time that we get someone else in that position and that goes regardless of party. National security needs to be priority number one and if you’re willing to play politics with our national security then you have no business serving in the Senate or the House.

Meadows, who has endorsed Rep. Mo Brooks (R-AL) in the U.S. Senate special election in Alabama, said that Brooks’s ad in which he promises to filibuster if the wall is not funded should be taken seriously.

“Mo Brooks is serious about making sure we fulfill our campaign promises ,and if anyone is willing to stand up to Leader McConnell on behalf of the people of Alabama it’s Mo Brooks,” Meadows said. “He’s not one that will make idle promises. If he says he’s going to filibuster until it gets done, everybody better bring their pillows because they’re going to have be staying there for a long time.”