Mark Sanford, a former governor and congressman from South Carolina, announced on Sunday that he will mount a primary challenge to Donald Trump in the 2020 presidential race.

“I’m here to tell you now that I am going to get in,” Sanford said on Fox News Sunday with Chris Wallace, after weeks of speculation regarding whether he will enter the race.

Sanford, who lost his House seat to a pro-Trump challenger in 2018, joins former Massachusetts Gov. Bill Weld and former Illinois House Rep. Joe Walsh in challenging Trump for the 2020 Republican nomination.

Sanford has focused his primary challenge around the issue of limiting government deficits and spending, which he says both President Trump and his Democratic challengers have ignored.

“I believe what’s happening in Washington needs challenging,” Sanford said in a video posted to his campaign website. “We’re heading toward the most predictable financial crisis in the history of our country.”

In 2009, Sanford, then Governor of South Carolina, faced scandal after admitting that he had been carrying on an extramarital affair in Argentina.

Following his Fox News Sunday appearance, Sanford tweeted a straightforward message on his decision to enter the 2020 race.

“I am compelled to enter the presidential primary as a Republican for several reasons,” Sanford wrote, “The most important of which is to further and foster a national debate on our nation’s debt, deficits and spending.”

Write to Alejandro de la Garza at alejandro.delagarza@time.com.