Sarah Sherry, 34, is fundraising for The Eye Fund, which was set up by her aunt and uncle following the death of her cousin Simon from a degenerative eye disease.

"When Simon was going through the disease his parents wanted to get him a counsellor but found there is only one in the whole of Britain who is trained to help people losing their sight," she said. "After he died my auntie and uncle set up the charity to change that."

And the fund has the backing of Sir Paul, who is the nephew of Sarah's auntie, Carol Sherry.

"We are a relatively new charity but Paul McCartney has helped us by putting in some money to make calendars which were sold," said Sarah.
She said she was confident of completing her 31-mile row and cycle in two-and-a-half hours.

Both will be on machines at Sudbury's Kingfisher Leisure Centre on Sunday.

"I have been training for it and I go to the gym every week anyway so, although it will be a tough effort, I hope I am prepared."