Sir Richard Branson, founder of the Virgin Group, will run with a team of celebrities including Natalie Imbruglia, Michelle Heaton and previous London Marathon women's champion Tegla Loroupe, while his children, Sam and Holly, are leading a group of 34 attempting to break the Guinness World Record for the most runners linked to complete a marathon linked together.

Here's what they said this morning:

Natalie Imbruglia, singer

"I've been training with the enemy- the caterpillar- but we've got a secret weapon in Tegla My knee has given me some trouble in training and I've had to change the way I run. I just want to make sure I run at my own pace and don't injure myself. My motivation is running for a great cause - Fistula - who I have been helping since 2005."

Michelle Heaton, model and singer

"When you get a personal email from Sir Richard Branson asking you to be a part of his team, it's a great reason to run the marathon. I did the New York Marathon last year but my finish time was really bad, probably the same time as the caterpillar is predicting for Sunday."

Tegla Loroupe, athlete and former London Marathon women's champion

"I met Richard a few years ago. He was interested in my work with the Peace charity. It's always a bigger motivation when you're running to help other people. Now I'm really happy to be training as part of his team and we should all have lots fun on Sunday."

The caterpillar

Holly Branson

"We're absolutely mad to be attempting this record but when it's for a good cause, it's all worth it. The record is 33 people and we've got 34 in our team, so let's see what happens on Sunday. I reckon we stand a good chance of breaking it."

Sam Branson

"There have been a few niggles during training. It's especially difficult to match up all our individual paces. Running for charity is the driving force and the one great connection we have between us all."

Phil Nevin, who dreamt up the caterpillar idea

"We're very proud of the team. They have shown commitment to this crazy idea and we're quite confident going into Sunday. It's been interesting having 34 individual opinions on the project but Sam and Holly are great people and have made it much easier than anticipated."