It has only been amplified this year after Lance Armstrong’s house of cards finally came crashing down, but after a week of answering essentially the same question every day – ’Can you assure us you are riding clean?’ – the patience of Froome and Team Sky began to run out yesterday.

“I just think it’s quite sad that we’re sitting here the day after the biggest victory of my life, a historic win, talking about doping,” said Froome, less than 24 hours removed from his stunning victory atop Mont Ventoux.

“My team-mates and I have been away from home for months training together and working our arses off to get here, and here I am accused of being a cheat and a liar.”

Sky’s problem is that, while there is no hard evidence against them, the doping scandals that have plagued cycling for so long now mean that those in yellow can find themselves assumed guilty until proven innocent, and proving innocence is extremely difficult.

Jonathan Vaughters, manager of the Garmin-Sharp team whose strict anti-doping policy serves as a means of redemption for himself and veteran rider David Millar – both guilty of doping infractions in the past – fears there is nothing Sky can do but wait for history to judge.

“People say: what is the solution? The solution is: you have to let time pass,” he said.

“In 10 years, my hope and belief is that we’ll look at this period and say: okay, it was true. Just like we look back 10 years now and say: It was false.

“I don’t see an immediate answer. How do we stop the scepticism? In a way it would be irresponsible to stop the scepticism. We have to be patient, and that is hard.”

Alberto Contador, the two-time Tour winner who lost his 2010 Tour title and served a ban for a doping infraction of his own, joined those calling for an end to the speculation.

“There is no reason to doubt Froome,” Contador said.

“He is a professional rider who has been performing at a really high level all year, and I think that his results are the fruits of the work he puts in and nothing else.”

Seeking a way to silence the doubters Sky team principal Sir Dave Brailsford yesterday suggested he would open the team’s doors to officials from the World Anti-Doping Agency who could study every element of their training program with an expert eye.

That will not happen in time to spare Froome further questioning at the Tour, but the 28-year-old insisted he would not be distracted in the final week.

“I can only be open. I know within myself I’ve trained very hard to get here,” he said.

“It’s been a long battle to get where I am now. I’ve had the support of a fantastic team. I can’t talk about anything outside of that.

“I know what I’ve done to get here.”