The Bishop of Lincoln will be spending a cold and uncomfortable night in a stable for charity.
The Right Reverend Christopher Lowson is hoping to raise £5,000 to support those without a roof over their heads.
He will have just a sleeping bag and a flask when he beds down for the night in a stable near Harmston in Lincolnshire in support of Christian Aid's Favela project in Brazil and the Nomad Trust, which works with the homeless.
The Favela project is working to improve the living conditions of families who dwell in the slums and work in the informal economy in downtown São Paulo, Brazil. Every pound raised for the project is match-funded by the European Union.
The Bishop was inspired by both the Christmas story and suffering of many without shelter around the world.
He said: "The nativity story is often romanticised into something rather charming and magical, and by doing this I hope to discover some of the harsh realities experienced by Mary and Joseph - and hundreds of people around the country and the world who have no bed to sleep in.
"Anything people can give to help me raise much-needed money for those in overwhelming need close to home, and those around the world, will be greatly appreciated."
The bishop will have some small comfort in the shape of a bed made from straw bales.
He is being supported by other clergy in the Lincoln Diocese who will also be braving the cold December night in stables across Lincolnshire.
Mara Manzoni Luz, Christian Aid's country manager for Brazil, said: "We'd like to say a huge thank you to Bishop Christopher for braving the cold conditions to raise funds for those in São Paulo in Brazil who are unable to find work and accommodation and have no alternative but to sleep on the streets or in favelas each night.
"We are grateful to all in his diocese and around the UK who are committed to ending the scandal of poverty and inequality."
Christian Aid Director, Loretta Minghella, added: "The majority of people living in extreme income poverty no longer do so in low-income countries, but are on the wrong end of inequality in middle-income countries.
"We thank Bishop Christopher for supporting Christian Aid's partners' work with marginalised communities living on the streets or in the favelas of Brazil."
To make a donation towards the bishop's target, visit www.charitygiving.co.uk/stablesleepout