Why are we "Ring Fencing" Foreign Aid?

[onyx39]

"Justice, energy and communities are among the departments agreeing to "significant savings", he said, adding that health, schools and foreign aid would be protected from cuts."

http://www.bbc.co.uk/news/uk-politics-22684993

I really do not get why we are exempting Foreign Aid for cuts? I could understand if the money went to the starving in Africa etc, but invariably it goes to countries like India who have very strong economies.