Three-time Tour de France winner Chris Froome has described the rules allowing athletes to take drugs that would normally be banned under sport's anti-doping rules as "open to abuse" and in need of urgent reform.
In a post on his Twitter feed, Froome said he does not have a "win at all costs" approach to sport and has never pushed the boundaries of what is allowed.
And in an apparent reference to the controversy surrounding his former Team Sky team-mate Bradley Wiggins, Froome said athletes need "to take responsibility for themselves, until more stringent protocols can be put in place".
Wiggins last week did an interview denying he was trying to gain an unfair advantage when he obtained permission to use a banned drug before some of his biggest races.
And Froome said: "It is clear that the TUE system is open to abuse and I believe that this is something that the UCI and WADA needs to urgently address.
"At the same time there are athletes who not only abide by the rules that are in place, but also those of fair play.
"I have never had a 'win at all costs' approach in this regard. I am not looking to push the boundaries of the rules.
"I believe that this is something that athletes need to take responsibility for themselves until more stringent protocols can be put in place."
