The Older Faces audit commissioned by the Anchor Trust revealed that only 20 per cent of presenters and actors on BBC One are aged over 50. By contrast, the proportion is 27 per cent at ITV1. While the BBC One features 28 per cent of older people in its news and current affairs programmes, ITV1 features 31 per cent of them.

Anchor's claims about BBC One follow the recent ageism row over replacing Strictly Come Dancing's Arlene Phillips with singer Alesha Dixon. However, the study revealed that 32 per cent of the BBC Two's presenters were over 50.

The research was carried out by PCP Market Research on five major terrestrial TV channels between 20 and 27 February and excluded imported programmes, repeats, films, regional programmes and shows that did not have a presenter visible on the screen. A BBC spokesman said a one-week sample study would not be an accurate reflection of BBC's year-long output.