Rep. Mo Brooks (R-AL), a Republican candidate for U.S. Senate in Alabama, is threatening to shut the government down in the U.S. Senate if his colleagues do not fund President Donald J. Trump’s planned border wall along the U.S. border with Mexico.

Mo Brooks, one of three major candidates in the race to succeed now Attorney General Jeff Sessions for Sessions’ seat, made the threat in a new ad set to air statewide in Alabama on television soon.

“Hi, I’m Mo Brooks, candidate for the Senate, and I approved this message,” Brooks opens the ad, titled “Build The Wall.” The ad was provided exclusively by Brooks’ campaign to Breitbart News ahead of its public release.

The ad then cuts to President Trump’s speech in mid-2015 at Trump Tower in New York City from the day he launched his campaign for president.

“When Mexico sends its people, they’re not sending their best,” Trump said in that speech, the clip of which is used by Brooks in the ad.

“President Trump promised a wall to keep us safe and to protect American jobs for American workers,” Brooks then says on camera:

But even some establishment Republicans are blocking the way. Elect me to the Senate, and I’ll fight every spending bill that doesn’t fund that wall. And if I have to filibuster on the Senate floor, I’ll even read the King James Bible until the wall is funded. And you know what? Washington could benefit from that. We’re going to build that wall, or you’ll know the name of every Republican who surrenders to the Democrats to break my filibuster. I give you my word, and I don’t give my word lightly.

WATCH THE AD FROM REP. MO BROOKS’ U.S. SENATE CAMPAIGN:

Brooks’ clarion call for border wall funding in the government spending bills coming up comes as many in the GOP establishment are not interested in standing with President Trump in ensuring that a wall is built on the U.S. border with Mexico. What he promises in this ad is a guarantee to fight as hard as a U.S. Senator can for the wall.

The race to succeed Sessions in the U.S. Senate is shaping up to be a very interesting one. Brooks, the pro-Trump candidate, is facing off against both former Alabama Supreme Court Judge Roy Moore and the appointed Sen. Luther Strange (R-AL). Strange was not elected to the seat but was appointed under questionable circumstances by now former Gov. Robert Bentley. Bentley has left office under a cloud of ethics questions.

Strange’s team and allies, filled with anti-Trump GOP establishment operatives, have been inaccurately accusing Brooks of being anti-Trump in a series of attacks on the ground in Alabama. Brooks actually supported President Trump during the general election, even donating to the president’s campaign, while Strange refused to publicly back Trump with donations or public comments.

The only evidence Strange’s team has against Brooks is that he was not on board during the primaries — when Strange was also not supportive of the president — so the attacks are ringing hollow throughout the politically-in-tune Alabama. Brooks is also very close with Attorney General Sessions, the former Senator whose seat he is running to fill. Brooks and Sessions repeatedly worked together in the U.S. Congress to advance the interests of America First priorities that later became a focal point of Trump’s campaign. Sessions has not endorsed a candidate in the race as he is the Attorney General.

But Trump allies like nationally syndicated radio hosts Laura Ingraham and Mark Levin, Fox News’ Sean Hannity, and Rep. Mark Meadows (R-NC) — the chairman of the pro-Trump House Freedom Caucus — have all endorsed Brooks in the race.

A highly connected GOP source with inside knowledge of Alabama politics who is closely following this race told Breitbart News that Strange is “like the Jeb Bush of this race. Nobody likes him. And while he’s got all this money and all these connections, nobody likes pro-establishment views. You can’t sell a product that consumers don’t like.” Also, given Strange’s allies and connections in the Washington establishment, there is likely no way he will ever commit to helping President Trump on his core campaign promise of building a wall on the border as much as Brooks has now in this ad.

Brooks was almost taken out by the shooter who opened fire on the GOP congressional baseball game practice, as he was one of many members at the practice. Brooks’ name actually appeared on the shooter’s hit list, though he was not hit in the shooting that has landed House Majority Whip Steve Scalise in the hospital multiple times.

The primary race is on Aug. 15, and the top two vote-getters are expected to head to a runoff sometime in September.