The top ten after today's stage - with Bardet holding onto his place on the podium by one second, Yates securing the white jersey and Contador moving about Barguil and into ninth place.
Marseille - Marseille
Tour de France - 22 July 2017
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So, it's a Polish-themed podium today as Maciej Bodnar takes the win by 1 second over compatriot Michal Kwiatkowski, with Chris Froome in third at six seconds.
Confirmation that Chris Froome is now 54 seconds ahead of Rigo Uran, with Romain Bardet staying on the podium by just one second! The Frenchman is 2:20 down, with Mikel Landa just one second further back.
Chris Froome was six seconds down on Bodnar, so it's just third place for the Team Sky man - who has all but won a fourth Tour de France.
Bardet comes home - just seconds ahead of Froome!
These long straights have not been kind to Bardet... he has Froome breathing down his neck!
Froome may well catch Bardet before they come into the stadium... that would be the ultimate humiliation!
OH NO! Uran slams into the barriers after overcooking one of the final bends! He manages to stay up on his bike, but that was a heart-in-mouth moment. He finishes 31 seconds down on Bodnar - and it should still be enough for second on GC. Well saved, Rigo!
Here's Mikel Landa - and he's 51 seconds down on Bodnar at the finish. Time will tell if it's enough for him to push Bardet off the podium.
Fabio Aru comes home 1'16" down on Bodnar's target time...
Froome could well catch Bardet at this rate - he crosses the summit not far behind the Frenchman... and three seconds slower than Bodnar.
Bardet is really suffering on this climb... he's in and out of the saddle, and pedalling squares. He could move below Landa on GC at this rate. He's 1'17" down.
Bardet is onto the climb now - and he skidded on the tight corner ahead of it. Uran is piling on the pressure - he went over the top 21 seconds down on Kwiatkowski.
Landa was 26 down at the first check and 33 down at the second check - so he could knock Bardet off the podium, but it's unlikely.
Froome is on course: he's only two seconds down on Kwiatkowski at the first check.
And Bardet is 45 seconds down, so it looks like the Colombian will move above the Frenchman today...
Uran is 26 seconds down at the first check...
Alberto Contador fades over the final quarter to come home in fifth place, 21 seconds down on Bodnar at the Stade Velodrome.
Fabio Aru is 38 seconds down at the first check... he's on the cobbled section now and has the climb coming right up.
Contador is on a storming run: he's equal with Kwiaktowski over the climb and is well poised to beat Bodnar's time at the finish.
Yates is 47 seconds down at the first check... meanwhile, Barguil is all smiles as he reaches the top of the climb, 46 seconds down on Kwiaktowski's effort.
Contador is sixth at the first check - 13 seconds down on Kwiatkowski's target time.
Chris Froome (Team Sky) is roughly 28 minutes away from winning a fourth Tour de France. He carries an advantage of 23 seconds over Bardet and 29 seconds over Uran - so he won't need to push too hard. But he will want to win a stage as well, so expect him to give it his all.
The crowds go crazy as Romain Bardet (Ag2R-La Mondiale) starts his effort... does he have what it takes to win the Tour in what is essentially Froome's back garden (when it comes to expertise).
Rigoberto Uran rolls down the ramp for Cannondale-Drapac. What a huge half an hour for the Colombian - this is his best ever shot at winning a Grand Tour...
Could Mikel Landa ride himself onto the podium and put himself in the shop window? There's talk that the Spaniard will leave Sky at the end of the season. He's down the ramp now, leaving just the top three to go...
Fabio Aru of Astana is back in blue and without his Italian national champion's jersey today. He wore yellow for a couple of days before cracking in the Massif Central and being hamstrung by apparent bronchitis in the Alps.
Ireland's Dan Martin is next up for Quick-Step Floors. He's 2:56 down on Chris Froome but we'll never know how much of a greater threat he may have been had Richie Porte not taken him out on the descent of the Mont du Chat in stage 9.
Simon Yates of Orica-Scott zips off - he's got to defend his white jersey from Meintjes today...
Louis Meintjes of UAE Team Emirates the next to roll down the ramp. Rumour has it he's heading back to Dimension Data next year...
Warren Barguil has gone full polka dot with the red bib shorts... while the climb will suit him, the Frenchman is not a great time triallist so don't expect great things from him.
Top ten time: Alberto Contador (Trek-Segafredo) rolls down the ramp - and this could well be the Spaniard's last chance to win a stage on the Tour de France.
Nairo Quintana - on course for his lowest finish in the Tour de France - rolls down the ramp. The Colombian has only ever finished on the podium in the Tour, but this year has slumped to 12th place after his failed attempt to win the 100th edition of the Giro d'Italia. This is his fourth consecutive Grand Tour and Quintana is wisely giving the Vuelta a wide berth next month.
French national champion Pierre Latour sets the 10th best time at the second check after the climb. And here comes Sylvain Chavanel, the French veteran of 17 Tours and former national time trial champion, who sets the sixth best time. Solid efforts from the two Frenchmen.
Roglic, after that bike change, could only post the 10th quickest time today - 49 seconds down on the leader, Bodnar.
NEWSFLASH: Warren Barguil, the polka dot jersey and winner of two mountain stages, has been voted the Super Combatif of the 2017 Tour de France. It was always going to be a toss up between him and the Belgian Thomas De Gendt, who managed to notch more than 1000km in breakaways. But it seems like Barguil's nationality got him over the line...
The current top ten...
Yes, Roglic was ninth quickest at the first check (25 seconds down) and ninth at the second check (38 seconds down) so it's not going to be his day.
Mechanical: Roglic has had to change his bike ahead of the climb so that may discount him from winning today. We're still waiting for confirmation of his time at the first check so we don't know whether he was on course of not.
This is how much Tony Martin put into that time trial... For now, he's third place after Polish duo Bodnar and Kwiatkowski.
Heartbreak for Michal Kwiatkowski! He crosses the line just over one second down on his Polish countryman, Maciej Bodnar, who stays in the lead.
Primoz Roglic (LottoNL-Jumbo) rolls down the ramp to get his ITT under way. The Slovenian is a time trial specialist but also showcased his climbing ability to win in Serre Chevalier in stage 17 after taming the mighty Col du Galibier. His opening TT in Dusseldorf was derailed by a crash in the rain - like half his team, it seemed - but today the sun is out, and Roglic will be one of the favourites to stand atop the podium in the Stade Velodrome.
There's your answer: Kwiatkowski is still in the lead at the second check, but his gap has come down to just one slender second after that climb.
Kwiatkowski is onto the climb so it's the moment of truth for the Pole...
Kwiatkowski is on a stormer! The Pole leapfrogs his compatriot Bodnar at the first check, setting a new target time at the 10.2km check of 11'53" - six seconds quicker than Bodnar. The Team Sky rider is lighter and has been climbing very well in support of Froome, and so he should - in theory - get up to Notre Dame much quicker than Bodnar.
It's the fourth best time for Stefan Kung, 34 seconds down on Bodnar at the finish. Interestingly, Team Sunweb's Nikias Arndt - the German who was outfoxed by Edvald Boasson Hagen yesterday - has set the third best time, 28 seconds down.
Huge cheers for Thomas Voeckler, who comes home to finish his last ever time trial on the Tour de France. The former French housewives' favourite - riding his 15th Tour aged 38 - retires at the end of this season. And he's not going to reappear on the podium: the Direct Energie rider sets the clock a hige 3'40 down on our leader, Bodnar. So, Thomas won't set tongues wagging tonight...
It will be interesting to see how Michal Kwiatkowski goes today - many have tipped the Team Sky rider to be among the favourites today. The Pole has been one of the riders of this year's Tour - working tirelessly for his leader, Chris Froome. Can he ride for himself today and show what he's capable of?
Stefen Kung was 10 seconds down at the first check and then 30 seconds down at the second check atop the climb, so it's looking like the Swiss won't challenge the top times today. It's been a shocker of a Tour for BMC who lost their GC rider Richie Porte to a crash in stage 9 and didn't see Greg van Avermaet pick up any wins. The Olympic road race champion has just started his ITT, incidentally.
CRASH: Just 20 seconds into his effort and Jonathan Castroviejo of Movistar skids out on the first bend outside the stadium - and the Spaniard needs to change a bike. He's already made it hard for him to be a factor today...
The Stade Velodrome is called such because it used to house a velodrome which, up until 1967, hosted 10 stage finishes of the Tour de France, as well as regular track events. The last time the velodrome was used for a cycling event was in 1972 for the world championships. The track then fell into disuse and in 1986 Bernard Tapie, the manager of l'OM pulled it up and replaced it with seating for the football stadium, which nevertheless kept the name of the Stade Velodrome as a reminder of its heritage.
It's good, but it's not good enough for Tony Martin: the world champion comes home 14 seconds down on Bodnar, who is in a good position to win this stage now - unless Chris Froome is feeling in good nick.
Stefan Kung, the young Swiss who finished second - behind Geraint Thomas - in the opening time trial, is on the course now, around seven minutes into his ride. The BMC man will be one of the favourites today.
Tony Martin came through the first check one second down on Bodnar. On the climb he stayed in the drops on those tri bars as he slow-motion steam-rollered past Daniele Bennati and Zdenek Stybar, a cascade of spittle and sweat pouring down his face and off his chin. But despite his obvious effort, the German was 14 seconds down on Bodnar at the 15.6km check and so he may struggle to make up the time on the Pole over the final quarter of the course.
Vasil Kiryienka is a former TT world champion but the Team Sky rider is clearly rather zonked after three weeks of working for Chris Froome: the Belarus veteran comes home 1'07 down on Bodnar's target time. Sutterlin then comes over a bit later 42 seconds down.
Could that be the winning time? Maciej Bodnar has come home to finish over a minute quicker than Taylor Phinney! Could there be life at Bora-Hansgrohe after Peter Sagan after all? The Pole's time of 28'15" won't be beaten for quite some time... unless Tony Martin is on a stormer!
Wow - Bodnar has smashed Phinney's time atop the climb of Notre-Dame de la Garde: the Pole comes through the second intermediate check in a time of 20'22 which is 51 seconds quicker than Phinney.
In fact, Phinney is now only the fifth fastest at the first intermediate check: Bodnar, Sutterlin, Kiryienka and Bak are all quicker after 10.2km. It's the Pole from Bora-Hansgrohe Maciej Bodnar whose time of 11'59 is the reference, 15 seconds quicker than Jasha Sutterlin of Movistar, with Phinney now 27 seconds back.
World champion Tony Martin is on course - so we will soon see just how good those reference times set by Phinney are...
Some stats on our current leader, Taylor Phinney.
World TT champion Tony Martin will be rolling down the ramp in seven minutes: the German from Katusha-Alpecin will be one of the favourites to win today, along with the likes of Chris Froome and Primoz Roglic...
The man who wore the Tour's first polka dot jersey is the man who leads this Marseille ITT: Phinney is still the man to beat, 50 seconds ahead of Albert Timmer.
The big guns won't be rolling down the ramp in the Orange Velodrome until much later today - these times are in CEST, so Chris Froome will be starting his quest for a fourth Tour win at 16:04 BST.
Earlier, Dutchwoman Annemiek Van Vleuten (Orica-Scott) followed up her victory on the Col d'Izoard with victory in the "chase" time trial for part two of La Course. She won the experimental pursuit by 1:52 over Lizzie Deignan of Great Britain, with Italy's Elisa Longon Borghini coming third another second back.
Phinney kept his form all the way to the end - and he has set the best time at the finish: 29min 21sec is his reference - 50 seconds quicker than second-placed Alberto Timmer of Team Subweb.
It's quite a location for the start and finish - the Orange Velodrome. And Rowe is the first rider to complete the course, coming home in a time of 31min 9sec.
British champion Steve Cummings is the latest rider to roll down the ramp. He hasn't been able to win a stage in this year's Tour - as he did for the previous two years - and he's unlikely to do so today or tomorrow. But you never know...
Here's Phinney tackling that tough climb to Notre Dame, atop of which he also set the best time at the second check. His target is 21:13 which is 55 seconds quicker than Wagner, which goes to show how big the time gaps could potentially be today in this short, but sharp, race against the clock.
As it stands, Taylor Phinney (Cannondale-Drapac) has set the fastest time at the first checkpoint at the Palais du Pharo after 10.2km. The American's target time is 12:26 - which is 19 seconds quicker than Robert Wagner of LottoNL-Jumbo. 14 riders have gone through.
And here's Luke Rowe grappling with that climb...
Here's a video of today's course, which takes the riders along the sea front of Marseille en route to a finish in the Stade Velodrome where Olympique Marseilles play their home games.
The first riders are already on the course, with Luke Rowe of Team Sky getting this decisive time trial under way. The Welshman is approaching the climb so we'll get our first taste of that 11% ramp soon...
Here's what the riders have to expect - a Madonna-on-her-back-circa-1990 of a profile, with that pointy climb up to the cathedral of Notre Dame the big challenge on an otherwise flat and fast course.
Yesterday, justice was finally done when Edvald Boasson Hagen soloed to a magnificent Stage 19 win in Salons-de-Provence - attacking from a break to turn his four winless podium finishes to a victory, as Chris Froome edged closer to a fourth Tour de France title after finishing safely in the pack.
Hello and welcome to live coverage of stage 20 of the Tour de France - the all-important 22.5km individual time trial in Marseille, where the destiny of the yellow jersey will finally be decided...