TRIVANDRUM, 20 June — In an unprecedented move, the normally unflappable Kerala Chief Minister A.K. Antony yesterday boycotted a press conference when confronted by journalists wearing black badges and black hoods. Immediately after the weekly Cabinet meeting ended at 12.40 p.m., Antony walked into the conference room for his briefing and was taken aback at seeing the protesting journalists. Folding his hands, he told them that there would be no briefing. Journalists have been on the warpath ever since assembly Speaker V. Purushothaman laid down new rules for television channels for covering question hour in the house.