ENTRECHAUX, France

There appears to be little to stop Chris Froome from reaching the Champs-Elysees on Sunday in the yellow jersey and becoming the second straight British cyclist to win the Tour de France.

After another brutal attack in the mountains on Sunday, Froome leads Bauke Mollema and Alberto Contador by more than four minutes with only six stages left — four of them suited to him. There is a time trial on Wednesday, followed by three straight days of tortuous climbs in the Alps.

But winning looks like the easy part.

The 28-year-old Froome’s physical superiority at the 100th Tour has raised eyebrows, practically inevitable in the climate of suspicion that haunts cycling after Lance Armstrong was stripped of his seven titles for serial doping.

This year’s race is the first since Armstrong lost his titles, and Froome understands the tone of the questions. Still, he was unhappy that doping became a main topic of his news conference on Monday’s rest day. That followed his stage win on Mont Ventoux, a mammoth climb in Provence that he tamed with two blistering attacks and where he left Contador — the 2007 and ‘09 Tour champion — lagging behind.

“I just think it’s quite sad that we’re sitting here the day after the biggest victory of my life … quite a historic win, talking about doping,” Froome said. “Here I am basically being accused of being a cheat and a liar and that’s not cool.

“To compare me with Lance, I mean, Lance cheated. I’m not cheating. End of story.”

With so many of cycling’s recent exploits later shown to have been drug-assisted, people understandably want to know whether they should continue believing. Froome’s performances are subject to intense debate on social media, cycling blogs and in mainstream media.

Dave Brailsford and Froome would much rather be focusing on the Alps.

And judging by what Contador saw on the 21-kilometer (13- mile) ascent up Ventoux, the Spaniard has every reason to fear more misery there.

If Contador thinks Ventoux was tough, then he will be dreading Thursday’s 18th stage — featuring two big climbs up l’Alpe d’Huez, one of the Tour’s most famed mountain passes.

That is bad enough, but Friday’s 127-mile trek from Bourg d’Oisans to Le Grand-Bornand looks horrendous.

There is simply no respite.

The day begins with two massive climbs, known as HC (Hors Categorie, essentially meaning they are beyond classification because they are so tough) and finishes with two nasty Category 1 climbs, a level just below HC but still incredibly hard.

For good measure, Saturday’s stage ends with a 10.7- kilometer (6.6-mile) HC climb up to Semnoz.

There is a glimmer of hope for Contador, however, because Froome’s Sky teammates have struggled at times. On two stages, Froome had to fend for himself. If that happens again in the Alps — and if he has a bad day — he could yet lose a serious amount of time.

“Yes, there is one stage I am looking at. It could be a good day to try something,” Contador said through a translator. “I’m going to look for an opportunity. In one week’s time you’ll know which one it was.”

Sky now has seven riders because Edvald Boasson Hagen retired with injury last week and Vasil Kiryienka missed the time cut on Stage 9.

“We lost a lot of our horsepower, our engine room,” Froome said. “Since then it’s been about managing the resources we do have and trying to get through each day as best we can. I feel the guys have done a fantastic job.”

Froome may need a little bit more of a cushion, though, and could target the 32-kilometer (20-mile) time trial.

The race resumes on Tuesday with a medium mountain stage from Vaison-la-Romaine to Gap in the Alps.