All of the commercial broadcasters are expected to be hit by the downturn.
Early indications show ITV suffering a 17 per cent decline, Channel 4 and GMTV down 10 per cent, and multi-channel and five experiencing at best zero year-on-year growth.
Last year, advertising for the World Cup buoyed revenues as advertisers increased TV spend. This year, however, those who hoped the end of war in the Gulf would lead advertisers to loosen their belts will be disappointed.
Nick Theakstone, the investment director at MindShare, said: "July and August could also continue to be a black hole. There are too many factors other than the war in play."
Because of June's dismal performance, the previous revenue gains made early on this year have been negated, and cumulatively the first half of the year is flat on the same period last year. January had proved to be relatively good for total TV, with revenues up nearly 5 per cent on last year, while April was buoyed by 7 per cent growth because of the Easter break.
During the past six months, ITV has only enjoyed one month of growth, and agencies are making early estimates that it could end the year down 5 per cent on last year. However, although the advance-booking deadline for July is just two weeks away, there is no clear indication of which way the market will go.
The news comes as the TV industry prepares to meet for its annual conference in Bath. While the disappointing ad revenues will be on the minds of the TV sales directors present, the Barb panel continues to disappoint the agencies.
Almost 17 months after its planned introduction, the panel is still some 300 homes short of its 5,100 panel-home target. London continues to be a particularly problematic area, with the panel 12 per cent short of its planned strength.