HRH The Princess of Wales drops the flag at precisely 9.30 this morning to start a record number of runners in this year's Mars London Marathon.

Approximately 25,000 will set out to run, jog or partly walk the 26 miles 385 yards from Greenwich Park to Westminster via the famous tea clipper Cutty Sark, over Tower Bridge and through the rejuvenated London Docks.

Eighty years ago the marathon was first run over this precise distance - then it was from Windsor to the White City Stadium in the Olympic Games of 1908. Today's top athletes like Hugh Jones and Charlie Spedding, both previous winners, are running not only to win but also for a place in the British Olympic team. Once again Norway's Ingrid Kristiansen looks set to be the first woman home with an enormous financial bonus if she is the first to break two hours 20 minutes. Live coverage of the whole race with commentary from David Coleman, Ron Pickering and Brendan Foster with additional reports on the route from Stuart Storey and Bob Wilson.