By Alan Baldwin LONDON (Reuters) -Frenchman Laurent Mekies got down to work as Red Bull team principal on Thursday, a day after replacing Christian Horner, and recognised big challenges ahead for the once-dominant former champions.

Christian Horner entered Formula 1 as its youngest team principal in 2005 and developed Red Bull from a “party team” to a serial title winner.

If Verstappen does leave, it would likely be for rival Mercedes.