Paula Radcliffe has conceded her world marathon record is under real threat in Sunday’s London race but says Mary Keitany and Tirunesh Dibaba may blow their chances by taking each other on too early in the contest.

Radcliffe’s time of 2hr 15min 25sec, set with the aid of male pacemakers, has stood unchallenged since 2003. But having run 2:17:01 in a women’s-only race last year – the second fastest time ever – Keitany believes that having male pacemakers this time will enable her to chase down Radcliffe’s record.

Dibaba is also said to be in fantastic form, leaving Radcliffe wondering whether her longstanding record might finally go. “The way Mary ran last year I thought for a long time it was under threat,” she said.

“So I think she is capable. But first and foremost she needs to concentrate on winning, because Tirunesh is highly capable too. But the record is very much down to how things are like on the day. You need good conditions, to have done the training and a bit of luck.”

Radcliffe admitted that a part of her would be “sad” if it was finally to go. “The longer it has gone on, the more I have become attached to it,” she added. “It has almost become part of the family. Did I think it would stand this long? Probably not. Do I want it to be beaten? No, but I can’t do anything about it. I can’t go out and reclaim it now.”

She also predicted a race for the ages – with Keitany establishing an early lead and Dibaba trying to reel her in. “Mary is going to go out and take the race by the scruff of the neck, while Tirunesh is far more likely to hold back until the second half of the race and see what she can do. Maybe that is the smarter tactic.”