Contador and Landa are absolutely flying up the lower sections of the Mur de Peguere.

They've staved off the chasing Quintana and Barguil, who are 30 seconds behind again, alongside Kwiatkowski, who is not helping to chase down his team-mate Landa.

Landa is now just 25 seconds away from becoming the virtual yellow jersey.

No surprises as Astana's Jakob Fuglsang abandons the race.

The Dane was fifth overall and looking strong but crashed on stage 11 - he held on to retain his position but it was later discovered he'd picked up two small fractures in his wrist and elbow.

Remarkably, he started and finished stage 12 but lost 27 minutes.

Even more remarkably, he started today but was off the back straight away. Smart decision to withdraw, he was unlikely to be any help to Fabio Aru with his injuries.

Contador and Landa are still just about out front alone and are approaching the lower slopes of the Mur de Peguere.

It's a category one climb - 9.3km long and a 7.9% average gradient, with sections at 18% - all followed by a descent into Foix.

Here we go...

If Chris Froome has the legs, then having two team-mates up front is an ideal situation for the Briton. He can just sit on Fabio Aru and Romain Bardet, forcing them to chase and then launch his own attack to bridge to his team-mates later on.

If Chris Froome does not have the legs, then Team Sky could be helping Alberto Contador win the stage.

Sky do have options - Mikel Landa could soon be the virtual yellow jersey on the road and might even take it at the end of the day.

Contador and Landa still out front by themselves on this descent of the Col d'Agnes.

Wonder if they've found time to chat about Landa moving to another team, perhaps to Trek with Contador, in search of a grand tour victory?

One for after the stage no doubt, given the frenzied nature of this stage.

Quintana, Kwiatkowksi and Barguil are about to join the Spanish pair up front.

There are currently 22 different groups of riders on the road.

Fantastic, mad racing.

Quintana, Kwiatkowski and Barguil are rapidly closing the gap to Contador and Landa - around only 20 seconds between the two groups now.

The yellow jersey group is a bit of a free-for-all right now.

Meanwhile, Contador and Landa are holding their lead over two minutes but Bardet's attack behind has cut into it.

Romain Bardet does indeed go on the attack on the descent, Chris Froome follows.

Fabio Aru under pressure but the Italian gets up to them, alongside Rigoberto Uran.

The group of overall contenders are up over the Col d'Agnes and onto the descent.

AG2R move to the front and will look to gas it down here - Romain Bardet is an excellent descender and could fray a few of his rivals' nerves before the final climb.

Contador and Landa have around 14km of descending to the bottom of the final category one climb of the day - the Mur de Peguere.

It was here on stage 14 in the 2012 Tour that tacks were thrown onto the road, causing almost 30 riders to suffer punctures.

A man who is looking for mountains classification points - Warren Barguil - attacks out of the second group on the road to take the six points left for third over the top of the Col d'Agnes.

Nairo Quintana and Michal Kwiatkowski follow.

Contador take first place over the summit of the Col d'Agnes, taking 10 points in the mountains classification, followed by Landa.

Neither are too fussed about the points, though.

This is a perfect duo in many ways for this situation - Contador is so far down on GC that he's been allowed to go and Landa isn't looking for the stage win so Contador is happy to work with him.

They're onto the descent.

Romain Bardet's team-mate Alexis Vuillermoz has been dropped by Nairo Quintana, Warren Barguil and Michal Kwiatkowski in the second group on the road.

Meanwhile, Contador and Landa are about to summit the Col d'Agnes...

Alberto Bettiol is doing a sterling turn on the front of the group of the favourites in service of his Cannondale-Drapac team-mate Rigoberto Uran.

The fourth-placed Colombian is looking calm on this chaotic stage so far.

The advantage of Contador and Landa over the yellow jersey goes above two minutes for the first time.

That could spark a reaction from some of the favourites - Landa is just 2'55'' behind Aru overall and the Spaniard is heading towards being the virtual leader on the road.

Froome will be happy to let Aru have to do the chasing, with no team-mates.

Rob Hayles
Former GB cyclist at the Tour de France

Probably today of all days was a good day not to have the yellow jersey, just because of the amount of action we're going to have.

Yes, they don't have to sit and ride all day, but there is so much expenditure on today's stage, all crammed into pretty much half the distance of most of the stages up to this point.

Trek's Bauke Mollema keeps dropping behind the other GC riders, only to doggedly scrape his way back up. Not sure how long the Dutchman can keep going that way.

Quintana is looking much better today - his group is about 40 seconds behind Contador and Landa, so about 55 seconds ahead of the yellow jersey group of Aru, Froome, Bardet, Uran and the rest of the favourites.

Mikel Landa finally comes through to do a turn and instantly takes his and Alberto Contador's lead out to 1'25'' - the peloton have slowed a bit but that's staggering power form the Spaniard.

It's been a thoroughly disappointing Tour for Alberto Contador so far. He's down in 11th, over seven minutes behind Fabio Aru.

But the two-time champion is rolling back the years right now. He's looking very strong.

There is a pursuing group of Nairo Quintana, Warren Barguil, Alexis Vuillermoz and Michal Kwiatkowski behind.

Quintana and Barguil riding for person gain, Vuillermoz and Kwiatkowski in service of Bardet and Froome respectively.