Stella Mccartney says it's a "once-in-a-lifetime opportunity" to design the Adidas competition wear for the 2012 Olympic Games.

The Fashion designer - who was announced last year as the creator of the sportswear firm's kit for both the British Olympic and Paralympic teams to wear at the London event - has already started work on the kits and admits it's a very exciting, but lengthy, project.

Writing for Gwyneth Paltrow's lifestyle newsletter GOOP, Stella said of meeting the team: "I arrive at adidas, it's a big day for me there as today I am showing the British Olympic Association my Team GB London 2012 concept. I am the creative director for adidas's team GB for the Olympics and the Paralympics. It's major and I am so excited! It is honestly a once-in-a-lifetime opportunity. I have a strong concept and today was about showing the BOA my direction. They were really positive ... It is totally just the starting points so just the very, very beginning concepts, but it's just to give an idea. (sic)"

The mother-of-four recently revealed she faces a "million challenges" when designing the competition wear.

She said: "I mean you're working with athletes. The main thing I want do is not in any way get involved with making their performance not its best. So for me I want to make them the best they can be.

"I'm obviously working with incredibly technical fabrics and dealing with silhouettes that I wouldn't normally perhaps work with.

"So there are challenges - I have a million challenges. I have to make it look good on TV, I have to make it feel good for the athletes, I have to make it work - technically it has to do its job. But I think they're all good challenges - I like a challenge."