The bishops were summoned during the Senate Blue Ribbon Committee investigation on the anomalies within the PCSO, with the bishops returning the vehicles donated to them. The CBCP Permanent Council also conducted its own investigation regarding the controversy. Senator Teofisto Guingona, chairman of the Blue Ribbon Committee, said that since the vehicles were used for secular purposes, the donation is not considered as a violation of the Constitution, but added that the issue was a "litmus test to the Constitution" since the Constitution prohibits favoring a particular religious organization. Senator Juan Ponce Enrile said that the tag "Pajero bishops" were unfair since the bishops did not received expensive vehicles and said that the PCSO leadership must be blamed for the controversy.