Thomas de Gendt sets off from Lure.

The Belgian is a very good time trialist and solid climber. If he's on good form today, he could trouble the top five on the stage.

Soren Kragh Andersen, who has won two stages in superb style this year, is out on the course.

There are 10 points on offer for the fastest rider up La Planche des Belles Filles followed by 8-6-4-2-1 for the next five quickest.

Then there is only one king of the mountains point left on tomorrow's stage.

Primoz Roglic could overhaul both Pogacar and Carapaz to take the polka dots along with the yellow jersey.

If two riders are tied after today, that battle for the sole KOM point tomorrow could be tasty.

1. Richard Carapaz (Ecu/Ineos Grenadiers) - 74 points

2. Tadej Pogacar (Slo/UAE Team Emirates) - 72

3. Primoz Roglic (Slo/Jumbo-Visma) - 67

4. Marc Hirschi (Swi/Team Sunweb) - 62

5. Miguel Angel Lopez (Col/Astana) - 51

In fact, Richard Carapaz's Ineos team-mate Pavel Sivakov confirmed earlier that's exactly what the Ecuadorian will do today...

He said: “The two Slovenians [Primoz Roglic and Tadej Pogacar who threaten the King of the Mountains leading position] are very good time trialists. Even doing the first part flat out, they’re able to do a very good time up the hill while Richard will save energy for the hill.

"We hope for the strategy to work out. Richard will of course change bike for the climb. We’re confident but not overconfident.”

Today isn't solely about the yellow jersey contest.

There are also king of the mountains points on offer for the six fastest riders up La Planche des Belles Filles, using their time from the start of the climb to the summit.

Richard Carapaz currently leads Tadej Pogacar by two points in the polka dot jersey and doesn't have the GC to worry about.

So Carapaz could well ease through the first part, change to his road bike and blast it up the climb.

After stage 19 yesterday, Tadej Pogacar refused to answer when asked whether he would change bikes today, saying it was a secret.

Unfortunately for him, UAE Team Emirates sporting director Allan Peiper gave the game away earlier today, telling reporters they are planning a bike change.

Unless that's a bluff?

Current leader Remi Cavagna: "I believe the favourites will beat me by 45 second to one minute. I dealt well with my efforts all along the course but I’m 77kg. It’s heavy.

"At the end, I wasn’t on my favourite terrain. I remained quite composed but compared to Primoz Roglic, I’ll lose a lot up the hill.

"I didn't change bike because I’m used to riding on my TT bike. Changing bike, I would have lost 30 to 40 seconds."

CCC Team's Alessandro de Marchi moves into second place with a time of 1hr 00mins 01sec.

So still just Remi Cavagna to have broken the hour mark so far.

15:56 - Alejandro Valverde (Spa/Movistar)

15:58 - Tom Dumoulin (Ned/Jumbo-Visma)

16:00 - Rigoberto Uran (Col/EF Pro Cycling)

16:02 - Adam Yates (GB/Mitchelton-Scott)

16:04 - Enric Mas (Spa/Movistar)

16:06 - Mikel Landa (Spa/Bahrain McLaren)

16:08 - Richie Porte (Aus/Trek-Segafredo)

16:10 - Miguel Angel Lopez (Col/Astana)

16:12 - Tadej Pogacar - (Slo/UAE Team Emirates)

16:14 - Primoz Roglic (Slo/Jumbo-Visma)

Current leader Remi Cavagna on Eurosport: "It was pretty tough out there but I'm pretty happy with what I've done. We'll sit and wait for Primoz Roglic to cross the line - I'm pretty sure he's going to win.

"But I've done the best I can and I'll sit in the hot seat knowing I've done the best I can."

Remi Cavagna remains the only rider to finish this 36.2km TT course in under one hour.

Benoit Cosnefroy, who wore the polka dot jersey from stage two to stage 17, comes across the line over four minutes down on leader Remi Cavagna.

Matt Warwick
BBC Sport

What a beautifully bizarre way to end the battle for the yellow jersey. After so much climbing – they were doing it as early as Stage 2 remember – we end with a time trial. Which has more climbing.

In terms of competition, it’s more or less over. Primoz Roglic is the best time triallist out of three vaguely realistic contenders – the others including Tadej Pogacar and Miguel Angel Lopez.

But the category 1 climb is so steep it’s expected that teams will wait somewhere on the course to change from a time trial bike to a conventional one to climb with.

It’s easy getting on and off a bike, right? For those who have to deal with the humble clipless pedal – which sometimes so mystifyingly fails to make that satisfying ‘clack’ as you pull away from the lights – we know it can be a risky business. And it’s against the clock. In the Tour de France.

So there’s potential for things to go very wrong. And Jumbo-Visma haven’t a had great couple of days in terms of equipment - a directeur sportif was excluded from the race following an overly heated exchange with a UCI delegate as they dismantled Roglic’s bike at the end of Stage 17, to check it for illegal assistance devices.

Some bikes in other races have had motors hidden within them to help riders climb; Roglic’s bike was fine, but the UCI’s routine checks clearly caused some frustration.

So it’s not all done and dusted – everyone’s feeling the pressure out there.

Image source, Getty Images

Danish TT champion Kasper Asgreen comes home second, 2mins 30secs down on team-mate Remi Cavagna.

Remi Cavagna stops the clock at 57mins 54secs - a full 3mins 05secs faster than previous leader Nils Politt.

Big statement from the French national TT champion.

That mark should last for a long time now - but is it enough to win?

The likes of Primoz Roglic and Tadej Pogacar will likely climb quicker so it could come down to how much faster Cavagna covered the flat start than they will.

Remi Cavagna used a 100km solo breakaway yesterday as a warm-up for today.

Tremendous power.

The Frenchman is 2km from the summit now.

Green jersey Sam Bennett, speaking to Eurosport: "I had a plan from my coach but I went a little over just to be sure I made the time cut as it's a climb you can lose a lot of time on. I wanted to be sure I would make it to tomorrow and I'm looking forward to that now.

"I've worked so hard to be in this position I didn't want to make any mistakes.

"I've got a lot of time to recover for tomorrow now."

Germany's Nils Politt has just set the new fastest time - 1hr 00mins 59secs.

He won't be spending long in the hot seat before Remi Cavagna arrives though.

Remi Cavagna has just caught and passed Tony Martin on the road.

The Frenchman is out of the saddle on his TT bike and kicking away. This is a supreme effort.

Former four-time world TT champion Martin started a full THREE MINUTES ahead of Cavagna.