Jane Tomlinson completed the New York marathon in five hours

The mother-of-three from Rothwell, Leeds, has already raised �1.25m and wants her toughest challenge yet to take her total past the �2m mark.

Her Ride Across America from San Francisco's Golden Gate Bridge to New York will start on 29 June.

Mrs Tomlinson will finish a course of chemotherapy just five weeks earlier.

The ride is due to end on 31 August - the sixth anniversary of the day doctors first told her she had just six months to live.

The 42-year-old has the full support of her husband Mike, 45, and children Suzanne, 20, Rebecca, 18 and Steven, eight.

She will be joined on the 62-day ride by two friends - Leeds Metropolitan University lecturer Ryan Bowd, 27, of Calgary, Canada, and 40-year-old Martyn Hollingworth, of Huddersfield, West Yorkshire.

She explained that after taking a year's break from fund-raising as her health reached a "precarious" stage, she was ready for another adventure.

"I've had a slow year, a year that's been very precarious health-wise, but this is something we've been thinking about for the last 14 or 18 months," said Mrs Tomlinson.

"It's something that we could get excited about. For us it's got to be something we would enjoy.

"I wouldn't go out there and increase the risk to my health. It will put a strain on me but I wouldn't be going out there if I didn't think I was well enough."

Last year, she announced she was retiring from charity work after completing the gruelling Florida Ironman contest.

But, following a course of chemotherapy, her health improved and she went on to complete the New York marathon last November in five hours 15 minutes.

Since being diagnosed with advanced metastatic breast cancer, she has also completed a 2,500-mile bike ride, from Rome to Leeds, as well as a number of triathlons.

In 2003, she received an MBE from the Queen and in 2004 won a Women Of The Year award with Olympic athlete Kelly Holmes.