Has the Big Brother bubble finally burst? The Channel 4 show has lost 25 per cent of its target audience since the racist bullying scandal that tainted the programme.

Figures seen by The Times reveal a disastrous slump in viewing for the latest series of the eviction show, which previously generated up to £50 million in revenues for Channel 4.

Another housemate will be evicted tonight. But after seven weeks of the current series, the average number of viewers in the key age range of 16 to 34 years is down from 1.9 million to 1.4 million viewers – a 25.6 per cent fall on the previous year.

The Barb/Infosys figures show that the average viewing audience across all age groups for Big Brother 8 is down from 4.5 million to 3.7 million – a fall of 16.7 per cent. The decline is worrying for Channel 4 since poor weather and the absence of a big football tournament on rival channels should have boosted viewing. Channel 4 is locked into a £180 million deal with producers Endemol to keep Big Brother on air until 2010.

Although Big Brother’s critics would welcome its terminal decline, Channel 4 would find it impossible to maintain its public service programming without the revenues it generates. Channel 4 announced yesterday that it will premiere a new film by the director Ken Loach about illegal employment in contemporary Britain. It is the kind of project Big Brother subsidises.

This year’s Big Brother was launched with a series of on-air apologies, for the bullying of Shilpa Shetty during the celebrity edition, demanded by Ofcom.

Yesterday a Channel 4 spokesman said: “Big Brother remains our most popular programme and continues to attract a huge amount of young, up-market viewers. While first and foremost an entertainment show, it is, as Ofcom acknowledge, an important programme that can raise matters of social importance which may lead to legitimate public debate.”

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