New Delhi, Sep 24 (ANI): Reacting on the reports of the possible TDP-NDA merger, Congress leader PC Chacko said that the popularity of TDP has reduced over the time and it is not effective anymore. He also said that the party is acting as an opportunistic party. As the BJP is leaving no stone unturned to gather new allies before 2014 LS polls, TDP chief Chandra Babu Naidu in a recent meeting with the BJP president Rajnath Singh had raised speculations of a possible tie-up between the two parties.