TVB last night brought forward its tabloid programme Focus on Focus to show it at the same time as rival ATV's Hong Kong Today show, which has a similar content.
ATV condemned the move and viewers also complained.
Popular Taiwanese drama Judge Pao caused a similar storm last year when both stations altered time-slots in an effort to outfox the other in ratings.
ATV said TVB's decision to move Focus on Focus from 10 pm to 8.30 pm violated agreements reached with the Broadcasting Authority after the Judge Pao row.
'It is unfair to viewers as the nature of the two programmes are quite similar,' said ATV programme manager Sandi Li Kit-ching.
'It is depriving viewers of their choice of programmes and it is also unfair to advertisers as we already have a large proportion of viewers committed to this time-slot. I feel the authority should be looking into this.' A spokesman for the Television and Entertainment Licensing Authority said it had received complaints from viewers outraged over the time change.
