Red Bull look set to block the introduction of the Halo head protection device next season, although that might not be enough to stop the FIA from making it a mandatory requirement in 2017.
The device is currently favoured by the FIA as it seeks to increase head protection in a bid to avoid similar accidents to Felipe Massa in 2009 and Jules Bianchi in 2014 – although it hasn't been proven how useful they would be against such incidents.
Ferrari trialled the Halo during pre-season testing and then ran with an updated version, the Halo 2, during Silverstone practice this weekend. Following that test, Sebastian Vettel raised some concerns about driver visibility.
Now Red Bull team principal Christian Horner, whose team designed a rival to the Halo which struggled during the FIA's crash tests, has said he would vote against its introduction.
"Personally I am not a big fan of the Halo," he told reporters. "I think it is an inelegant solution to the problem it is trying to deal with.
"I would prefer there to be more research time taken to do the job properly rather than rushing something through that may have other consequences. I am not a big fan of the Halo and the limitations that it has.
"I certainly wouldn't vote in favour at the moment," he added.
Teams are set to vote on its introduction this month with a final decision due at the end of July. A majority is required for it to succeed and it's believed a number of team bosses share Horner's feelings toward the Halo.
However that may not be enough to stop its introduction, as the FIA can force through changes on safety grounds.
