Former House Speaker Newt Gingrich (R-Ga.) is "highly unlikely" to meet the criteria for participation in the first presidential primary debate set for May 5 in South Carolina, according to a spokesman. 

Gingrich spokesman Rick Tyler said that despite committing to the debate, it's unlikely Gingrich will be able to attend, given the criteria laid out Monday.

Fox News Channel, which is co-sponsoring the debate with the South Carolina GOP, outlined criteria Monday afternoon that would force candidates to make a decision by the end of the month about whether to get in the race if they want to participate in the debate.

In order to take part on May 5, candidates must register a presidential exploratory committee or have announced a formal campaign for president by April 29.

"It is highly unlikely that we will meet the criteria to participate," Tyler said in an email. "Specifically, the April 29 requirement does not fit within our time line."

Gingrich told reporters on Capitol Hill late last month that he would make an official decision on a presidential bid by the beginning of May, and it appears unlikely he's willing to move that timetable up, even by a few days, in order to get onstage for the May 5 debate. 

"We're trying to finish out the exploratory process, and I think by the first week of May, we'll have done that," Gingrich said late last month.

At the beginning of March, Gingrich announced the formation of a website to "explore" a 2012 bid, but stopped short of formally filing papers for an exploratory committee.

Along with Gingrich, former Minnesota Gov. Tim Pawlenty, Rep. Ron Paul (Texas), former Sen. Rick Santorum (Pa.) and former Louisiana Gov. Buddy Roemer have all committed to participating in the May 5 debate, but only Pawlenty and Roemer have filed an exploratory committee with the Federal Election Commission.