The life-long friends have their padded cycling shorts packed and ready for the 300-odd mile cycle from London to Paris which starts on June 18 with the Discover Adventure organisation based in England.

Mandy, who runs her own recruitment consultancy in Belfast, and Sharon, a business development and marketing manager with the Southern Regional College in Armagh, are each taking part in the challenge to raise money for two separate charities.

Mandy hopes to raise around £5,000 for the Christian Stauros Foundation, which works with people with addiction problems, while Mandy has chosen the Northern Ireland Cancer Fund for Children. She hopes to add around £1,500 to the £10,000 Southern Regional College students have already raised through their COPE (Certificate of Personal Effectiveness) course at the Armagh campus.

"We have never done anything like this before, but we decided to take on a new challenge and spend some fun time together, while at the same time raising money for really good causes," said Mandy, who has two young sons - Rowan (2) and Spencer (4). "In my case, the Stauros Foundation is very close to my heart, as my parents, Tom and Linda Eakins, have been involved in helping people through the foundation for over 25 years."

The girls will be leaving behind their husbands and children for a week when they fly out to London on June 17, ready for an early morning start the next day at Greenwich, London.

"Day one of the itinerary is definitely the most daunting for me, as I will be worried we won't make the boat for Calais in time," said Sharon, mum to Ethan (7) and four-year-old Joe. "Also, the first day we have to cover the most miles, 95 in total, so we'll have to make sure we don't get lost!"

With Mandy the 'organised one' of the two and Sharon more technically talented - she can change a wheel 'in no time' according to Mandy - they seem perfectly matched as they negotiate the winding country roads of France, where cycling is the national sport and where many an interested onlooker will often stop and cheer on the various passing cyclists who pass through their village.

"We have been preparing since Christmas, and we go out cycling the roads when we can, but even if we thought we were fairly fit beforehand, working on an exercise bike in the gym is nothing like the real thing - where you have to cope with the weather conditions, traffic and keeping focussed on direction signs," said Mandy. "Of course, padded shorts are vital and the right energy-giving foods and drinks are important in preventing cramp and keeping you going!"

Their route brings them through medieval market towns in northern France, passing through the famous battlefields of the Somme and Agincourt, before triumphantly cycling up the Champs d'Elysee and finishing under the lofty arches of the iconic Eiffel Tower.

"The cycling is fairly tough and there will be some strenuous hill climbs, so when we eventually arrive in Paris we will feel like cheering," added Sharon. "I know I will feel on top of the world, having safely reached our target destination - even with a few aching limbs - and having raised a lot of money for our charities en route.

"We will both miss our families, but the mobile phones will be coming with us, so we can keep everyone at home up-to-date on our daily progress. We are both viewing the cycle as a mental challenge as well as a physical one, so that will be another hurdle to overcome - hopefully, we're both up to it!"

Anyone who would like to make a financial donation towards the girls' fund-raising efforts can do so by logging on to www.justgiving.com/mandycollie or www.justgiving.com/sharonwilliamson1.