She is joining Scottish charity workers today in launching the urgent appeal in the wake of spiralling food prices.

People can help by donating money or taking their old clothes and other items to city Oxfam shops.

The charity said successive droughts, violent conflict and chronic poverty, have put an estimated nine to 13 million people in urgent need of humanitarian assistance. This situation has been compounded by rapidly rising food prices.

Oxfam's Rob McNeil, who had just returned from Ethiopia, said: "This is a catastrophe in the making, but we have time to act to before it becomes a reality. The cost of food has escalated by up to 500 per cent in some places, leaving people who have suffered drought after drought in utter destitution.

"People are increasingly becoming desperate. I saw people in one village reduced to pounding the food pellets intended for their animals into porridge to feed their families. We fear that the worst could be yet to come."