The party emphasised on the need for discipline and improving its image at a meeting of its office-bearers in Delhi to discuss the strategy and issues ahead of polls in six states and the Lok Sabha elections.
While the BJP top leadership maintained that the political situation prevailing in the country was strongly anti-Congress and favoured the main opposition, there were concerns that this opportunity may be frittered away due to the actions of some leaders.
Mr Singh, who convened the meeting for the first time since he announced his team of office-bearers on March 31, said some leaders of the party have been speaking out-of-turn to the media and without being authorised to address the press.
He also said some party leaders have been "announcing" names of Prime Ministerial candidates "virtually on a daily basis" which created unnecessary controversy. This, he said, got highlighted diverting attention from the party's achievements.
Mr Singh's comments came against the backdrop of growing clamour in the BJP for projecting Gujarat Chief Minister Narendra Modi as its Prime Ministerial candidate.
Delhi BJP chief Vijay Goel also created a flutter with his remark on Saturday that the next government at the Centre will be formed under L K Advani's leadership.
The meeting was attended by Mr Advani, BJP Parliamentary Party chief, Leader of Opposition in Lok Sabha Sushma Swaraj, her Rajya Sabha counterpart Arun Jaitley, central office-bearers and presidents and general secretaries of the state units. Gujarat Chief Minister Narendra Modi also attended the meeting.
The party leadership felt Lok Sabha elections could be held any time after November while polls were due in Rajasthan, Madhya Pradesh, Chhattisgarh, Delhi and Karnataka. Polls might also be held in Jharkhand which is under the President's Rule.
In his address, Mr Advani said BJP had lost in 2004 due to "over-confidence" and there was a need for caution this time.
Party workers should use their full potential and not become complacent, he said.