The artist formerly known as Cat Stevens has released He Was Alone to benefit his refugee charity Small Kindness, and he has enlisted the support of many celebrities to put the word out about the track.

As well as Penn, Kim and Miley, Yusuf has also called on Pete Townshend, Blondie, Ricky Gervais, Naomi Campbell, Queen, Sheryl Crow, Emma Thompson, and Jude Law to help promote the single using the hashtag, #YouAreNotAlone.

"While the world faces incomprehensible numbers and statistics created by the refugee crisis, the tragedy and story of a single soul gets missed," the Morning Has Broken singer-songwriter explains.

"It was difficult to stand by just watching this tragedy without trying to do something. I simply decided to help humanise the narrative and lend my voice to the call for keeping hearts and doors open to every refugee, especially youngsters, who have lost what future they might have once hoped for."

As Cat Stevens, Yusuf was a major folk star in the late 1960s and 1970s, releasing 11 acclaimed albums, including Teaser And The Firecat, Foreigner and Buddha And The Chocolate Box, before retreating from music for almost three decades after converting to Islam.

He returned to the music scene in 2006 with the album An Other Cup, and has since released two new albums - Roadsinger and Tell 'Em I'm Gone.