A LAWYER is planning a triathlon challenge that will take him five days to complete in three different cities and two different countries.

Mark Thompson, 42, will start by completing the London Marathon on April 13, then swim a mile in the pool at Bannatyne's Gym in York Business Park, Poppleton, and finish with a 300-mile cycle ride from London to Paris on July 25 to July 27, arriving in time to see the finale of the Tour de France.

He hopes to raise thousands of pounds for Children with Cancer.

"I am nervously ready to go," said the York criminal law solicitor. "I am determined not to fail. I will keep going, knowing that no matter the aches and pains and traumas I will go through are absolutely nothing compared to what children with cancer and their families have to go through."

Mark has been running for years and completed some 10k runs. He also trains twice a day at the gym. Then, for the first time in his life, he got a place at the London Marathon, and decided this was the year he would achieve a major fitness challenge.

He has spent the winter training hard, including doing much longer runs than he is used to.

He has already won backing from his solicitors' firm, M & A Solicitors, from the New Park Court Chambers of barristers in Leeds, and from the gym.

And he hopes the mile long swim will be a family affair with his partner Sarah Harvey and her two children joining him in the pool. He will have to complete 84 lengths of the 20-metre pool to achieve his goal. He has yet to set the date.

The London to Paris ride will be as part of an organised group ride and he has a donations webpage at virginmoneygiving.com/MarkThompson2014