The former Archbishop of Canterbury Rowan Williams is using his Christmas message to urge support for famine-stricken countries such as Sudan and Burkina Faso in north and west Africa.

In a message recorded for the aid agency Christian Aid, Dr Williams said the heart of Christmas was the 'very simple image: a new-born baby lying exposed in the cold of winter'.

Now a life peer, Master of Magdalene College and honorary professor at Cambridge University, Dr Williams described the picture of the baby Jesus as a 'very powerful image of our own vulnerability, our own weakness, in the face of the environment'.

He said: 'At Christmas, we naturally think of those of our fellow human beings who live daily with exposure and vulnerability, and will put back in touch just a bit with our own vulnerability, with the fact that, in spite of everything, we're not in charge of our world.'

Dr Williams is chair of Christian Aid and called for support for its Christmas appeal as he said, 'life doesn't have to be like this. We can build a world with deeper justice, greater fairness, greater security for all.'

He said: 'One of the most serious forms of powerlessness that anyone can experience is, of course, hunger. Take a country like South Sudan: after years of merciless and bloody civil war, food security has become a major question in South Sudan. This year, a famine was declared. Countless young people faced starvation. It's not the only place in Africa, or indeed throughout the world, where this is a problem. Places like Burkina Faso are facing some of the same challenges.

'But South Sudan is particularly vivid in my own memory: I visited there a couple of times in the last 10 years. I've seen what life is like in the refugee camps. I've seen the feeding programmes, combined with educational programmes, that many local churches and charities take up. The challenge is enormous, and it's one that we are determined to face this Christmas, and to respond to. A gift of £10 will feed a family in South Sudan for a week. A gift of £40, for a month.'

He added: 'We can embrace the exposed, new-born child in Bethlehem, by embracing those who are exposed and naked in the world today.'

You can donate to Christian Aid's Christmas appeal here.