The actor Tom Hiddleston, the model Naomi Campbell and the presenter Jeremy Clarkson are among the famous names that are supporting a social media campaign that asks people to take selfies when they wake up to raise funds for Unicef.
The #wakeupcall campaign was the brainchild of the journalist Jemima Khan, a Unicef UK ambassador, who wanted to raise awareness and funds for children who have been forced to flee their homes because of the civil war in Syria.
Khan, who last month visited Jordan to see the work Unicef is doing to help displaced Syrian families, posted a picture of herself on Twitter taken after she had just woken up and challenged other celebrities to do the same and make donations to the charity.
"Please help make my campaign to raise awareness & money for Syria's 6.5 million children affected by the conflict a success: #WAKEUPCALL," she wrote on Twitter.
Khan nominated the actor Hugh Grant, the singer Lily Allen and Clarkson. Clarkson tweeted a picture of himself lying next to the chef Heston Blumenthal.
Participants are asked to make donations of £5 to Unicef by text.
This is the latest in a series of social media campaigns to benefit charities, including the ice bucket challenge and #nomakeupselfie – the main difference is that this has been set up by Khan with help from Unicef rather than developing organically.
A Unicef spokeswoman said it was too early to say how much money had been raised but donations were so far "in the thousands".