One key reason for keeping Sergio Perez at Red Bull has just fallen away.

Despite public backing for Perez from billionaire Carlos Slim over the weekend, it's now been revealed that Telmex, the Mexican driver's largest Slim-affiliated sponsor, will no longer appear on the Red Bull car in 2025.

Red Bull recently announced an "expansion" of its partnership with American telecom giant AT+T, a direct competitor of Telmex, especially in Mexico. Slim, acknowledging this development, admitted that Telmex's deal with Red Bull may soon come to an end.

"We are in talks with the team," Slim stated. "We are still talking to them, but the intention will always be to continue to support Checo. We will continue to support him without a doubt."

Slim clarified that Perez's contract with Red Bull is separate from the team sponsorship deal. "Checo's contract is separate from our sponsorship contribution to the team. It has always been like that since we have been with this team.

"But if we no longer have the opportunity to work with the team, we will definitely want to continue with Checo."

Even though Telmex's departure may be looming, Slim emphasized his commitment to supporting Perez wherever he ends up. "The intention is to continue that collaboration, regardless of which team Checo is with."

This latest development adds to the mounting speculation that Red Bull and Perez, 34, could also be headed for a split.

Red Bull team boss Christian Horner expressed frustration over the team's current situation.

"We are now only third in the constructors' championship," Horner said. "As a team, we have done everything we can to support Checo and we will do the same in Brazil."

"But there comes a point when we can't do any more. That is the point at which difficult decisions have to be made," Horner concluded.