ALL THE ACTION AS IT HAPPENED (ALL TIMES BST)
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1230: A quick word from Dan Robinson before we go: "I'm quite satisfied. The plan was to finish top Brit, run a personal best and confirm my Olympic selection, which I'm pretty sure I've done."
Good luck to everyone still on the course - you're all legends.
1215: Ronan Keating is closing in on Ben Fogle, which is a sentence no man should ever have to write.
1210: The rain's eased off now as the thousands of fun runners pound their way round. The Masai warriors are taking their time, while James Cracknell is miles ahead of Jonathan Pearce, who to be frank is struggling. But enjoying himself immensely.
1203: A happy Liz Yelling, confirmed as ninth in a big PB, has a word with Sue Barker. "I'm delighted," she says. "I'm not sure I did the best tactical race, but I really pushed hard over the last six miles."
1200: Here comes Tomas Abyu. Not the best day for the Brit - that bronchitis he had a few weeks back has left him way off his best.
1155: Baldini has prevailed - but Robinson has a personal best by a clear 40 seconds. 12th place for the Stroud battler, and that's a super effort.
1154: Baldini's ahead by a metre.
1153: Robinson and Baldini are going stride for stride over the final half-mile. Which one will prevail?
1151: Six personal bests for the first six men across the line, with US tyro Ryan Hall coming home a fine fifth.
1150: Martin Lel it is - that's his third win in four years, a new PB and new course record of 2hrs 5.15. Wonderful finish from the great champion. Wanjiru takes second, Goumri third.
1150: Lel makes the break.
1148: 500m to go - Wanjiru wants to lead this one out.
1147: Goumri is dropping back. It's Wanjiru or Lel for the win.
1146: Neck and neck. Goumri tried to break away turning towards Westminster Square but the others responded.
1145: The three pass Embankment tube station. Goumri or Wanjiru have to take the sprint finish out of Lel.
1143: Lel is looking effortless. Wanjiru seems to be working hardest. Two km to go.
1141: Merga's gone - it's now down to Wanjiru, Goumri and Lel. Brilliant run from the youngster, but Lel is looking extremely comfortable. The world record is likely to be beyond them, but the London record is still on.
1138: Not such good news for Tomas Abyu - he's dropping back, and at the moment won't get the qualifying time he needs to make the Olympics.
1136: Dan Robinson having a blinder in 13th place, heading for a personal best and a guaranteed place at the Olympics. He's even going to catch Olympic champion Baldini - sensational.
1133: Those four men battle past the Tower of London. Which one of them will have the finish?
1131: Lel, Wanjiru, Merga and Goumri are clear in the men's race. The pace dropped around the 20-mile mark, which allowed Ryan Hall back into the group, but they've upped it again. Just under 1hr 44 at 35km.
1129: Brilliant run from Hayley Haining too - she smashes her PB in finishing just under the 2hrs 30 mark.
1128: Here comes Liz Yelling - she's on for a brilliant PB, and is well clear of Haining. 2.28:30-odd for Yelling, well inside the Olympic qualifying time, and that should book her place in the GB team for Beijing.
1126: Shelly Woods comes home third in the wheelchair race, looking hugely disappointed.
1123: It's going to be Irina Mikitenko's day - the 35-year-old German crosses the line in the pouring rain to take her first ever marathon win in 2hrs 24.13. Zakharova takes second, 25-odd seconds back, and Wami will finish third. The Ethiopian is limping badly, and that fall at Canary Wharf must really have cost her.
1121: The leading men have gone through 30km in 1hr 28mins - which means Martin Lel has set a new Kenyan record for 30km.
1119: Rain now pouring down on the streets of London, and Mikitenko is hanging on to her lead with just two km left.
1117: Mikitenko has a lead of eight seconds over Zakharova, and she's really hurting. Wami is 21 seconds off the lead. Does Zakha have anything left?
1115: Seven miles to go in the men's race. Wanjiru heads Lel. Mutai, Merga and Goumri still on their heels.
1113: Mikitenko has made a break for it along the Embankment. Neither Wami nor Zakharova can hang on, and this could be the key moment. Just two and a half miles to go, and Wami looks finished.
1111: Shelly Woods now in third in the wheelchair race, but it looks like Sandra Graf will take the win in a new course record.
1108: Changes in the men's race - Ryan Hall has been dropped, and it's Lel, Mutai and Wanjiru, plus Morocco's Goumri and Ethiopia's Deriba Merga. What a race this could be.
1107: Yelling has started to open up a gap again over Haining. Her mouth is hanging open with the effort.
1103: Back to the battle of the Brits - Yelling looks over her shoulder and sees Haining only 15 seconds back. She tries to accelerate. Both still set to go under 2hrs 30secs.
1100: Mikitenko has made a big break. Wami goes with her and Zakharova clings on too, but Petrova and Adere have both been dropped. 35km gone.
1058: Incredible scenes in the men's wheelchair race - seven men are together coming round the final corner. David Weir puts in a big burst and the others can't respond, and the Briton has retained his title. There's a pile-up behind him, and two racers have crashed into the advertising hoardings.
1057: Wami takes a stint at the front. Petrova and Adere respond.
1055: Still world record pace from the men - Haile Gebrselassie's mark could be in genuine danger. Will they tire over the second half of the race?
1053: Wami is running like a woman possessed - she's managed to work her way back to the leading pack, although how much that effort has taken out of her we don't know. Adere hits the front with Germany's Irina Mikitenko right on her shoulder. Souad Ai't Salem, who also hit the deck when Wami went down, is nowhere to be seen.
1051: Shelly Woods is a minute down now on the leaders in the wheelchair race. The defending champion has work to do.
1050: The top men have gone through 20km in 58mins 58 secs. Lel, Limo, Wanjiru and Hall all still there.
1048: Dan Robinson is having a good race - he's in the third group, but so is Tomas Abyu. It's all happening.
1045: This race between the British women is really hotting up - the gap is down to 16 seconds between Yelling and Haining. Dark clouds gathering overhead.
1043: Drama in the women's race - Wami slips and falls at the feeding station by Canary Wharf. It takes her a while to get back to her feet, and she's now a good 30 metres down on the leaders.
1042: Yelling's gone through 25km 21 seconds ahead of Haining.
1037:The leading men are still hammering along. Nine athletes plus two pacemakers in the group, with an enormous gap to the next group. 4mins 45 for that last mile, which is rapid in the extreme, but no-one wants to drop off the group for fear of being left to run on their own.
1033: Hayley Haining is starting to close on rival Liz Yelling - only 20 seconds or so back. Liz is going through a tough patch, and that Olympic place is up for grabs.
1031: Three more join the leading women's group as the pace drops again, and Petrova goes to the front. Wami and Adere both looking very comfortable.
1028: Right - the diversion at the gas-leak is a chicane to take them to the other side of the road. It will add in total a mere two metres to the length of the race, which means any times will stand as records. Good work, organisers.
1026: The leading men are about 90 seconds inside the world record at the moment. 11 in the group, including Lel, Limo, Wanjiru and Hall.
1023: The problem is at the 14-mile mark, apparently. The diversion would be small, but it could be key. Meanwhile, Wami and Adere are in a group of four women who have gone clear at the head of the field.
1021: Breaking news - that gas leak at Canary Wharf means the elite women's race is going to be re-routed. It's only a small part of the route, but there's a chance now the distance won't be bang on - and that could spell bad news for Yelling in her Olympic quest.
1020: News on the British men - Tomas Abyu is in 15th, having gone through 10k in 30.36, with Dan Robinson 30 seconds back in 22nd. That's very fast for both, but particularly for Tomas.
1016: World champion Luke Kibet is 30 seconds off the main group; Baldini a further minute back. This is the fastest start we've ever seen to the London Marathon - well inside world record pace - and it could blow the race apart.
1014: Very, very fast pace in the men's elite race. Baldini's been dropped, which isn't a huge surprise, but the leaders have gone through 10km in 29.10 - which is 2hrs 4mins pace. Madness.
1010: Yelling approaching the halfway point in great shape. Reports are coming in of a gas-leak at Canary Wharf, which could in theory cause huge problems for the race. I'll keep you posted.
1008: Very tight at the front of the men's wheelchair race, but David Weir is right up there. Could be a sprint finish on The Mall, which would suit David all over.
From petetheplane on 606: "Congratulations to Simon Beresford, the first ever Downs Syndrome sufferer to complete the London Marathon last year, followed by the Berlin marathon. Good luck for today's marathon from all your friends at the Lichfield Health &Fitness Club."
1005: Tomescu-Dita takes the lead in the women's race, but only in the sense of leading a pack of about eight. Liz Yelling still on for a PB.
1001: Martin Lel grabs his drink at the first feeding station. A group of about 10 athletes has split away and is being led along by two pace-makers, with all the big contenders tucked in behind them.
1000: More on Yelling - she's about 30 seconds off the lead group and has gone through 15km in 51.57 - which would see her finish in around 2hrs 28mins.
0956: Shelly Woods is in the leading group of four in the women's wheelchair race, looking very comfortable.
0952: There's been an injection of pace in the women's race, and Yelling has dropped off the main group. No bad thing that - she's still leading her closest British rival, Haining, by around 35 seconds, and to follow the pace of the main group would be madness.
0950: Alarming scenes in the wheelchair race - as the leading contenders catch up with the slower women from the elite start, there's a pile-up in the narrow section.
From Gerry via text: "Good luck to all running today, I'll be with you in 2010 with guarateed place after eight times of applying!"
0945: Martin Lel's starting off in a black woolly hat. He shakes hands with Felix Limo. Olympic champion Stefano Baldini is wearing cycling arm-warmers, while American prodigy Ryan Hall is hidden behind shades. Dan Robinson's lurking there somewhere too - and and there goes the hooter. Bon chance.
0940: It's a sea of humanity down at Greenwich - the elite men are being walked to the start-line, with the nervous masses behind them.
From T1mlnOz on 606: "Good Luck from here in Melbourne to my brother, Robin Herringshaw 39469, running his 1st Marathon for the RNLI Lifeboats. Wish I was there to be cheering him on."
0933: Changes in the women's race - Haining has dropped back as the pace quickens, but Yelling is right there. Liz reckons she's in the best marathon shape of her life, and she's looking smooth as she passes the Cutty Sark.
0928: Gordon Ramsey and Graham Poll at the start line, but that's as much publicity as I'm giving those two chronic self-aggrandisers.
0922: Almost ready to go in the wheelchair races. David Weir and Shelly Woods looking to defend their titles, but the field is rammed with talent. Good tattoos from the powerhouse that is Weir.
From TC via text: "GOOD LUCK TO BIG DEE,HE HAS TO WEAR HIS WIFES KNICKERS."
Easy on the caps, TC.
0915: Thinning out at the front of the women's elite race - Scotland's Haining has gone to the front to drive the pace along after that turgid first mile. Yelling is right with her - both of them chasing a time close to 2.26.
0911: Phil Daniels and Amanda Holden join Sue. Holden gives it some 4hrs 30 chat; Daniels hints at waiting for a bus.
From pablue on 606: "I fancy Ryan Hall for an impressive showing in the men's race. If he's in anywhere near the form he was in at the US olympic trials then he'll be there or there-abouts. Putting in a 4.20 mile at mile 18 to blow away the field on a tough Central Park course is unbelievable stuff."
0909: Any thoughts on our possible winners today? London specialist Lel to ping through at the death again?
From marathon9 on 606:"Morning Tom..must admit to being a tad jealous this morning as I was not accepted this year, but I would like to wish all the best everyone running today. Hope they all have a lovely day and raise loads for their chosen cause..GOOD LUCK ALL!"
0906: As you'd expect with the elite women so far - a large group with all the big names is easing along. The first mile takes just over six minutes, and that's about as cautious as it'll be.
Via text: "Paul Beeden - good luck darling - we r so proud of u love ya lots sue an jolly up x ."
0900: And we're off - a mournful hooter sounds, courtesy of Sebastian Coe, and the elite women cruise away.
0855: The elite women are lined up at the start. No Paula, of course, but Liz Yelling and Hayley Haining are battling it out for a place in the GB squad for the Olympics. Gete Wami looks chipper; Berhane Adere just cold.
0850: It's like the TV Quick Awards bash down there at the moment - here's BBC football commentator Jonathan Pearce. "I'll trundle round - waddle it," he says, unconciously name-checking two footballers plus an England coach in a single sentence.
0845: Ronan Keating and Kelli from Eternal chat to Sue. Keating is sporting a wispy ginger beard which looks dangerously trampish. "I'm looking forward to the energy on the streets," he says, a line which may well appear as a lyric on his next long-player.
0840: A rosy-cheeked Sue Barker chats to James Cracknell and Ben Fogle at the start. Cracknell is aiming for a sub three hours time - useful - while Fogle seems a touch nervy. Not surprised, given his performance at the World Coal-Carrying Championships three weeks ago - he finished a weak-legged 22nd, four places behind your correspondent. He did beat my colleague Ben Dirs, but then again Dirs struggles to take a lift without wheezing.
0835: A chilly six degrees down at Greenwich. Due to get a bit warmer later on, but there are showers on the way too.
0828: Latest odds on the elite races: Gete Wami is favourite for the women's contest at 9/4, just ahead of Berhane Adere at 5/2.. Salina Kosgei, Constantina Tomescu-Dita and Svetlana Zakharova all around the 12/1 mark.
Martin Lel is 3/1 favourite for the men's race, with Sammy Wanjiru 7/2 and Felix Limo at 5/1.
0820, via text: "Happy birthday to Victoria Tompkins from daddy Martin Tompkins, running today for Cystic Fibrosis trust."
0810: Morning all - the day has dawned bright and cold in south-east London. Just an hour till the elite women get under way, with the elite men due off at 0945.
Here's a little treat for you to enjoy over breakfast - a print-off-and-keep guide to all the big names in the elite fields.
I say all the names - I had to cap it at nine, but if you need any cheeky facts about anyone not in there, drop me a line and I'll rustle something up.