Nielsen Media Research faces mounting pressure to delay the introduction of its people meters in Chicago and Los Angeles.

The pollster wants to deploy the system, used for national TV ratings since 1987, to gather local data in these two prime markets.

Critics, however, maintain the system which would dispense with diaries and the old set-top boxes is flawed. They claim the system would underestimate black and Hispanic viewers.

Nielsen says the protest by the self-styled, Don't Count Us Out Coalition, has been orchestrated by Fox television owned by Rupert Murdoch. It argues that the old system was inaccurate and overestimated local audiences.

The pollster wants to switch to people meters in the 10 largest markets, including Chicago, Los Angeles, San Francisco and New York by 2005. Boston was converted two years ago.

Last month, however, it was forced to postpone the New York launch, after a protest from the coalition. Following the intervention Nielsen promised to investigate the claims.

Data sourced from: New York Times; additional material content by WARC staff