John Cornyn Senate Minority Whip John Cornyn (R-Tex.), on  June 11 on Capitol Hill. (J. Scott Applewhite/AP)

Sens. John Cornyn (R-Tex.) and Mike Johanns (R-Neb.) said Monday that they will vote against a border security compromise fashioned by Sens. Bob Corker (R-Tenn.) and John Hoeven (R-N.D.).

And Sen. Richard Burr (R-N.C.) will also oppose the compromise, Post Politics has learned. Burr has yet to publicly announce his position on the bill.

Cornyn's decision is not a huge surprise, given that he sponsored a more restrictive border security amendment and voted against the immigration bill in committee. But it does signal that there will be significant dissent when it comes to the Corker-Hoeven compromise.

"I cannot support an amendment cobbled together at the eleventh hour that doubles the border patrol without knowing how much it will cost or whether it is even the right strategy," Cornyn said in a statement. "

Cornyn cited the lack of a "trigger" in the border security deal — something that delays a path to citizenship until benchmarks are met. Cornyn's amendment contained such triggers.

“The same tired approach of crafting a piece of legislation that does nothing more than throw money at the problem simply won’t cut it," he said.

The loss of Johanns is a bigger deal, considering he is retiring after the 2014 election and was seen as a potentially gettable vote.

“I recognize our system is broken but the solution begins with border security so we aren’t back in this same spot a decade from now,” Johanns said. “Unfortunately, this amendment’s promise of secure borders is not airtight. Additionally, several organizations representing our border agents and related personnel say this bill weakens national security and prevents them from doing their jobs."

Elsewhere, a coalition of conservative groups, led by the American Conservative Union and Ralph Reed's Faith and Freedom Coalition, issued a statement in support of the Corker-Hoeven amendment. Many of these groups had previously been supportive of the immigration reform effort.

Adding the trio of 'no' votes now makes nine Senate Republicans who will vote against the bill. Sen. Rand Paul (R-Ky.) became the sixth Sunday, citing the Senate's rejection of his own border security amendment.

According to The Fix's latest immigration bill whip list, 51 senators are definite supporters of the bill, an additional 10 are likely to support it, and three more are considered potential "yes" votes. If all of them vote that way, the bill will receive 64 "yes" votes — close to the 70 that supporters would like to get to.

Updated at 2:41 p.m.