A bench of Chief Justice S H Kapadia reserved their orders after hearing arguments from various sides, including those by Prashant Bhushan, counsel for petitioner Centre for Public Interest Litigation, Thomas` counsel K K Venugopal and Attorney General G E Vahanvati.
During the hearing, the bench wanted to know if the the Leader of the Opposition can have a veto power in the process of CVC`s appointment.
Leader of the Opposition is one of the three members of the high-level panel headed by the Prime Minister and also comprising Union Home Minister, for the CVC`s appointment.
Advocate Prashant Bhushan pointed out that the purpose of having the Leader of Opposition on the panel was to ensure that the government does not steamroll the selection process.
During the hearing, senior advocate Venugopal argued that irrespective of placement of all materials before the panel, the process of appointment will not be vitiated.
He said the consultation process is independent of the material placed before the panel.
He also questioned the court for holding a judicial review over the issue of appointee`s integrity saying whether the panel looked into it or not is not for the court to enquire into.
Venugopal said the panel functions as a recommending body on the basis of which the President appoints a person as the CVC and nobody knows what materials are considered.
He said the CVC`s appointment is not based on the recommendation by the Council of ministers and an independent decision is taken by the panel.
He also said the President is the appointing authority and there was no challenge to this aspect.
He said Thomas` appointment was justified as a Kerala government order had clearly said that no case was made out against him in the Palmolein import case, nor was he under suspension and was appointed as the state government`s chief secretary.
Venugopal followed the government`s line of argument that there was also no challenge to the CVC clearance given to him on the basis of which he was appointed as secretary in the Central government.
Referring to the electoral law which said that merely filing a chargesheet in a criminal or corruption case against a person does not disqualify him from contesting elections, Venugopal contended that a person is rendered ineligible to contest only after his conviction in the case.
He also said that it is nobody`s case in this court that necessary materials were not placed before the panel.
Attorney General G E Vahanvati said once the file on the appointment goes from the Prime Minister to the President, the assent is given.
"Once the recommendation goes from the PM, it is binding on the President to give assent," he said.
Bhushan opposed the contentions made by counsel for Thomas and the government justifying latter`s appointment as CVC. He said the selection has to be unanimous and not on the basis of the majority decision of the panel.
There cannot be any compromise with the criteria of integrity and conflict of interest which has been raised by the CPIL in its petition, he argued.
He said the additional ground required for CVC`s appointment has emerged during the hearing of the petition as it has become clear that the relevant materials like the chargesheet pending against him in a Kerala court, the sanction to prosecute him and the two judgements of the court dealing with the chargesheet was not considered by the panel.
Thomas was appointed CVC on September 7 last year, but various civil societies like CPIL and some eminent persons including former Chief Election Commissioner J M Lyngdoh have moved the apex court against his appointment as head of the anti-corruption watchdog.
The petitioners have contended that Thomas cannot be considered as a person of "impeccable integrity" as a chargesheet was filed against him in the Palmolein import scam when he was a secretary in the Kerala Ministry of Food and Civil Supplies. He had secured bail from a local court.
The petitioners have also alleged that he was appointed despite strong objections from from Leader of the Opposition in Lok Sabha Sushma Swaraj who was a member of the panel.
The petitioners also said he could not be appointed the CVC on account of "conflict of interest" as till recently he was serving as Telecom secretary and that there was allegation that he was involved in the "cover-up" of the 2G spectrum scam.
The Comptroller and Auditor General (CAG) in its report had said that the loss to the exchequer as a result of spectrum licences being given to certain companies at undervalued prices was to the tune of Rs.1.76 lakh crore.