ISLAMABAD - PPP Co- Chairman Asif Ali Zardari summoned Rehman Malik, the Advisor on the Interior from the Judges Committee meeting and asked him to explain on whose directions the by-election had been postponed. He also telephoned NWFP Chief Minister Amir Haider Hoti, well informed sources said. According to the sources Asif  Zardari expressed extreme displeasure for Rehman Malik and the explanation extended by him was rejected. Prior to Rehman Malik's arrival at Zardari House a special meeting of the important PPP leaders was also held in which the postponement of by-elections was mulled. All the leaders attended the meeting suggested that the postponement of the by-elections was a conspiracy against and demanded that the secret hands behind this conspiracy should be brought to light, the sources informed. As per PPP sources the prominent leaders of the party have demanded the replacement of the Advisor on Interior Rehman Malik without delay. Meanwhile, the PPP spokesman Farhat Ullah Babar has said that he was surprised at the statement of the NWFP govt. He said that the PPP was not in favour of this postponement, however, Rehman Malik would talk about this matter himself.