Former GOP campaign rivals are joining forces in Louisiana to defeat Sen. Mary LandrieuMary LandrieuYou want to recall John McCain? Good luck, it will be impossible CNN producer on new O'Keefe video: Voters are 'stupid,' Trump is 'crazy' CNN's Van Jones: O'Keefe Russia 'nothingburger' video 'a hoax' MORE (D-La.) in next month’s runoff election.

Col. Rob Maness, the firebrand Tea Party candidate, is expected to deliver his endorsement of Rep. Bill Cassidy (R-La.) on Monday, the Times Picayune reported Saturday.

Maness said he and Cassidy “had a positive discussion concerning our shared love for our country and for Louisiana” during a double date with their wives on Friday, he later wrote on Facebook.

“I shared with Bill some thoughts on ways to grow our party and keep our elected officials more connected to those they serve. Before it was over, Bill even helped me put a new bumper sticker on our Truck,” Maness posted.

Maness and Cassidy will be the guests of honor on Monday at a Republican rally headlined by Sen. Rand PaulRandal (Rand) Howard PaulCongress must end American support for Saudi war in Yemen Black men get longer prison sentences than white men for same crimes: study Sarah Palin on sexual harassment: 'People know I'm probably packing' so they 'don't mess with me' MORE (R-Ky.) and Louisiana Gov. Bobby Jindal.

Maness’s stamp of approval comes after months of campaigning against Cassidy, making a tougher race for the GOP. The conservative, who has been endorsed by former vice presidential nominee Sarah Palin, received about 14 percent of the vote, which helped force the race into a runoff.

Landrieu is largely running her reelection effort solo after the Democratic party pulled a multi-million ad buy this week. Republicans are working hard to seal the win, sending 220 staffers to canvass the state before the December 12 runoff.