The Enforcement Directorate (ED) on Thursday termed the anticipatory bail granted to Congress leader P Chidambaram and his son Karti Chidambaram by the trial court in the Aircel-Maxis case as 'unwarranted'.In its plea to the Delhi High Court challenging the anticipatory bail of the father-son duo, the ED said the pre-arrest bail to Chidambaram and his son was 'unwarranted' and the trial court's finding that the offence was not grave enough was completely "perverse and untenable" in law.It said that the position of Chidambaram and Karti that they are members of the Rajya Sabha and the Lok Sabha respectively cannot be a legally tenable ground to grant them anticipatory bail.The ED asked the Delhi High Court to set aside the trial court's order and cancel the anticipatory bail of the duo and said that the trial court failed to appreciate that the custodial interrogation of the accused was required.The probe agency said that they both remained evasive during the investigation."There is a .