The President, Ratu Josefa Iloilo, did not have any powers to appoint Voreqe Bainimarama Prime Minister as his "emergency powers were only within the context of the 1997 Constitution".
That was the submission of Nye Perram, who is representing Laisenia Qarase and others in their case against Commodore Bainimarama and others in the High Court.
Mr Perram said the court needed to determine what the Constitution said about the President's "executive powers" and whether it was lawfully applied following the events of December 5, 2006.
He said the Constitution upheld values of the rule of law and it was the role of the judiciary to determine what the powers of other branches of Government were.
Mr Perram said it was clear the Constitution was the supreme law of the land and it established the hierarchy of laws in the country.
He said the High Court had the jurisdiction to determine all constitutional questions brought before it.
He said the Constitution allowed the court to deal with constitutional cases so that the key notion of the rule of law was always guaranteed.
"Section 120 subsection 2 of the Constitution states the High Court has original jurisdiction in any matter arising under the Constitution or involving its interpretation."
He said the Office of the President determined its powers from the Constitution.
"Therefore, the President is a creature of the Constitution."
He said the Constitution stated the executive authority of the State was vested in the President, who was the head of State, commander-in-chief of the Republic of Fiji Military Forces and had powers to establish the office of the Vice-President.
He said the President could only be removed for the inability to perform the functions of the office whether arising from infirmity of body, mind or any other cause like misbehaviour.
Mr Perram said in the absence of a President, "the VP performs his functions and in the absence of both the Speaker of the House of Representatives steps in".
He said Commodore Voreqe Bainimarama's actions "as a soldier to take control of government on December 5, 2006, could never be lawful".
Mr Perram said no provision in the Constitution allowed Mr Bainimarama to be President when he assumed executive authority in December 2006.
"He obviously was not a man helping the country in a crisis but someone justifying his appointments after he sacked people, including the Commissioner of Police and Cabinet ministers," said Mr Perram.
He said the President only acted lawfully on the advice of the Cabinet or the Prime Minister and that he had no powers to exercise on his own.
He said Commodore Bainimarama could never be appointed as PM because he was not a Member of Parliament and that the President had no powers to make that move. He said the Constitution clearly referred to an elected prime minister and Commodore Bainimarama was not and Mr Qarase was still the Prime Minister as he had not resigned and had not received a pension.
"This government is, therefore, unlawful and non-existent, and came to power using a gun and this court has the powers to give the regime its place.
"None of Qarase's Cabinet ministers have resigned as the only way to do so is through writing to the President and it is, therefore, clear that these people were deprived leadership through the takeover, and had applied for pension because they did not have a choice and were under duress," he said.