Parliament's Public Accounts Committee ,PAC, has summoned corporate lobbyist Niira Radia and Tata Group Chairperson Ratan Tata on April 4 to discuss their role in the 2-G Spectrum allocation case. Representatives of four key players namely Reliance (Anil Ambani Group), Airtel, Swan Telecom and Unitech, have been summoned on April 5. Sources in the PAC said that the panel will meet on 4 and 5 of April to discuss the 2-G spectrum allocation case which had led to the resignation of Telecom Minister A Raja. He was later arrested and is still in custody.Earlier editors of 'Outlook' and 'Open' magazines were called in the 2-G spectrum case to question them on the revelations made in their respective publications about tapes regarding Radia's telephonic conversations with captains of industry and important journalists. The PAC has already been briefed by CAG, CBI Director and many other people in connection with the probe. PAC Chairperson Murli Manohar Joshi as well as several members of the panel had expressed satisfaction and happiness with the deposition made by the editors of the magazines. The call has come after the JPC Chairman P. C. Chacko suggested that PAC should confine itself to its mandate and not go beyond it.