The Pirates of the Caribbean star is urging fans to donate to a festive drive launched by editors of Britain's The Independent newspaper in aid of Great Ormond Street Hospital (GOSH), where Lily-Rose Depp, now 16, was treated for kidney failure.

Johnny's girl was admitted to the facility at the age of seven after she was struck down with a near-fatal bout of E.coli poisoning while her father was shooting a movie in London.

The actor has now written a tribute to the doctors and nurses at Great Ormond Street to back the newspaper's Christmas fundraising appeal.

"The darkest days of my family's life were spent within the walls of Great Ormond Street Hospital (GOSH)," Johnny writes. "It was... the most frightening period of our lives.

"But, owing to the phenomenal care shown by all the staff at Great Ormond Street, they not only brought us continued hope on a daily basis, but ultimately saved my daughter's young life.

"I was amazed to witness the nurses, doctors, and all involved, approach their work with such great diligence and purity of heart... I was profoundly moved and I will be forever grateful and eternally beholden to these infinitely courageous, kind and professional individuals.

"And hence, I wholeheartedly support this appeal and thank the papers and you, the readers, for supporting such a worthy cause. I hope people dig deep and give generously to this magical hospital so it can continue to be a home away from home for very sick children and their families..."

Editors of the newspaper add in a statement issued at the launch of the appeal: "For our charity appeal this year, The Independent is supporting Great Ormond Street Hospital (GOSH)... Because of its long history, there is also a desperate need to relocate many of the wards out of ageing infrastructure and into more modern buildings. This can't all be done without your generosity."