I plan to cycle from the foot of the Eiffel Tower to the foot of Nelson's Column in the space of 24 hours – dismounting, of course, to cross the Channel from Dieppe to Newhaven – over the last two days of July. It's a distance of about 170 miles, and even more in kilometres. I have done it twice before, but I am older now and creakier, and being sponsored to complete the course will be a huge incentive. Please note that I am meeting all the expenses involved out of my own pocket, so all my sponsorship goes to charity.

The Cambodia Trust does unfashionable but life-redeeming work, providing artificial limbs for people crippled by landmines or polio in one of the world's poorest countries. I have supported them since 1990, when they bought a redundant prosthetics factory in Italy and shipped it out to Phnom Penh. You can read more about what they do at http://www.cambodiatrust.com.