"If the weather is nice it's possible to run 2:04 here, or even 2:03," Kebede told a news conference on Thursday.

"If the body is healthy, and the weather good, I think on Sunday I will run the world record."

Gebrselassie set his world mark of two hours three minutes 59 seconds on the fast Berlin course in 2008.

The only world mark in 30 London marathons was set by American Khalid Khannouchi in 2002 when he finished ahead of Gebrselassie on the Ethiopian's debut over 42.195 kms.

Kebede, 24, who clocked 2:05:19 last year, is the fifth fastest man only in Sunday's race which once again features the cream of the world's marathoners.

Four Kenyans are ahead of him on the all-time list, headed by James Kwambai, who recorded 2:04:27 in Rotterdam two years ago. Only Gebrselassie and Duncan Kibet, who beat Kwambai to the line in Rotterdam, have run faster.

Patrick Makau, last year's Rotterdam and Berlin champion, is next on the list with 2:04:48, followed by world champion Abel Kirui (2:05:04) and three-times London champion Martin Lel (2:05:15).

Kirui, who finished fifth last year, said he had learned from last year's mistakes.

"My mistake last year was to push with Kebede," said Kirui. "The day before the race we were challenging each other about who was going to win. We were mocking each other.

"So in the race, when the two of us were together, I thought, `I have to beat him'. But it was too much for me.

"This time I will control myself so I can finish better. Of course, I hope to win, so I am not going to worry about the world record. If I am in a position to do well, if my body feels good and the weather is okay, then there is no obstacle to doing it here."

Russian Liliya Shobukhova is aiming to break 2:20 in her defence of the women's title she won last year after finishing third on her marathon debut over the London course 12 months previously.

"Of course it will depend a lot on the weather but with the quality of the field we have here I think I can run sub-2:20," she said. "My training has been going really well, in Portugal and at home in Russia, so I am confident."

Temperatures are forecast to reach 18 degrees Celsius on Sunday with sunny intervals and light winds.