Bradley Wiggins faces a tough task to retain his 2012 Tour de France title after the route for next year's race was unveiled in Paris.
It remains unclear if Wiggins will be Team Sky leader at the 2013 Tour or if Chris Froome will be granted the role in a race which features 65km of individual time-trials and four summit finishes, including to Mont Ventoux.
The 100th Tour's route - the first since Lance Armstrong was stripped of his seven titles - will end on the Champs-Elysees at night and will be less advantageous towards Wiggins' time-trial prowess.
Tour director Christian Prudhomme revealed a 3,360-kilometre, 21-stage route, which takes place entirely in France, beginning on Corsica on June 21 and finishing under floodlights on the most famous boulevard in Paris on July 21.
The decisive blows in the battle for the yellow jersey in 2013 could come on the 18th stage, which features, for the first time, two ascents of the 21-turn Alpe-d'Huez in a race which incorporates all the fabled climbs.
With a route that would certainly favour his rivals it would be understandable if Wiggins was not involved next year but the Briton was still yet to fully appreciate what he would face. "It is hard to tell because I haven't really seen it in a lot of detail," he said. "It is a lot to take in in 10 or 15 minutes, it doesn't count for a lot at the moment."
Team Sky principal Dave Brailsford was keeping his cards close to his chest about the team's plans for 2013.
"We had the first and second-placed riders in last year's Tour and it puts us in an interesting position for sure going in to next year's planning," he told Sky Sports News.
"Bradley is the reigning champion but the whole excitement about today is to see what the course is like and that will dictate our plans for the team next year. Once we have established what the course is like then we'll make sure we lay our resources to the best of our ability so that a Team Sky jersey is the best placed to cross the line or win the race overall.
"It's not about one rider or another but about the team, to put our best team out to try and win the race."