Phongthep was representing Yingluck in answering a motion submitted by Democrat MP Rangsima Rodrassamee.
“After the court has issued the ruling, the prime minister instructed the Council of State to study the ruling in detail to advise the prime minister what to do next,’ Phongthep said.
He said the prime minister needed the advice from the advisory body because the ruling was unprecedented.
In the motion, Rangsima demanded that Yingluck take responsibility for sending the amendment bill, which the court has ruled unconstitutional, for a royal command.
In his reply, Phongthep argued that Yingluck was required by the Constitution to submit the amendment bill for a royal command within 20 days after its approval in the final reading by the Parliament.
Phongthep also pointed out that Yingluck knew nothing about the voting on behalf of peers by certain Pheu Thai MPs. The practice was cited as one of reasons by the court to declare the bill unconstitutional.