Channel 4 head of programmes Julian Bellamy has warned that consolidation among independent production companies could have a dramatic impact on the availability of current affairs programmes in the future.

"Most of my career was in current affairs," he said. "I know more than most just how important current affairs is."

When questioned as to whether his plans to clump programmes together would impact Dispatches - with rumours of the channel signing an output deal with Wall to Wall to theme documentaries - he answered:

"Broadly speaking, one of the issues facing current affairs is supply. As indies get bigger, they become less inclined to make current affairs."