Bracing for embattled U.S. Rep. David Rivera to be indicted or lose his election, Republicans have started lining up potential successors to regain the seat in 2014 if the congressman’s Democrat opponent defeats him in November.

The pressure has been building for about a month, but it boiled over last week after a series of stories by The Miami Herald and El Nuevo Herald documented that a candidate suspected of illegal campaign activities linked to Rivera has turned on the congressman.

For the past week, a group of Miami Republicans began mulling possible future candidates, who might even challenge Rivera in 2014 should he win the election in November.

Leading the list: Jeb Bush Jr., son and namesake of the popular former governor, and state Sen. Anitere Flores. Other names include Marili Cancio, a lawyer who challenged Rivera in the 2010 GOP primary; former state Sen. Alex Diaz de la Portilla, who’s running for state House, and Miami-Dade School Board Member Carlos Curbelo.

None could be reached for comment, except for Cancio, who said “whoever is in the race will beat Joe Garcia. We can’t afford to have him in Congress.”

But Rivera’s own trusted political adviser is concerned.

“David faces a real Herculean task to keep his campaign together,” said Dario Moreno, a Florida International University political science professor who polls for Rivera.

“Everyone at a political gathering was talking about this,” Moreno said, declining to name names about the meeting of Republicans.

Making matters worse for Rivera, on Friday The Herald obtained a survey conducted by GOP pollster McLaughlin & Associates that showed Rivera losing to Democrat Joe Garcia 33-43 percent.

The 10 percentage-point margin is outside the 4.9 percent error margin for the 400 likely-voter survey taken in the newly drawn District 26 that stretches from Kendall to Key West. A Democratic poll earlier in the month showed Garcia with a 9-point lead.

The Republican poll could hurt Rivera’s already anemic fundraising, and that in turn could make it difficult for him to hire campaign staff.

“McLaughlin is the pollster for the Republican Party and is very well-known and respected,” Moreno said, echoing comments from political consultant David Custin, who has led efforts to defeat Garcia in the previous two congressional races.

“It looks bad for Rivera,” Custin said.

Still, Moreno said Rivera is pinning his hopes right now on two points: “Joe’s unpopularity with Cuban exile voters. Joe still has a big Cuban problem. Second, it’s too late for the Republicans to recruit a candidate at this late hour to hold the seat.”

Rivera told Channel 41’s America Noticias on Monday that he has been down in polls before and still won.

He has denied wrongdoing.

“No federal agency has said or confirmed that I am under federal investigation,” Rivera told America Noticias.

Rivera also accused Garcia of being under investigation, although he cited no federal agencies, and federal sources told The Herald it isn’t true. “This is obviously a lie from a very desperate man whose party is trying to find a replacement for him,” said Jeff Garcia, a spokesman for the Garcia campaign.

Republican leaders are trying to determine who could step up if Rivera left office before the Nov. 6 election, even though his name would remain on the ballot.