Defence minister Pranab Mukherjee poured cold water on the recent initiative by a section of state Congress leaders to forge an electoral understanding with the Trinamul Congress for the coming byelections in three Lok Sabha and one Assembly seats in West Bengal. Byelections will be held for Katwa, Purulia and Malda Lok Sabha constituencies and lone Bangaon Assembly constituency on September 16. Commenting on the raging pesticide-in-cola controversy, Mr Mukherjee said that if the laboratory reports revealed the presence of hazardous substance in soft drink, the government would certainly take appropriate measures.