Rep. Juan Miguel Zubiri (Lakas, Bukidnon) said such a measure would be achieved on the same ground that the Sandiganbayan dismissed over the weekend Estradas petition that he be placed under house arrest.
"It runs in conflict with the Constitution. The only way to allow it is to amend the Charter," he said.
Zubiri was reacting to reports that Estrada allies in the House of Representatives and the Senate are planning to file a bill allowing house arrest for certain privileged prisoners.
The plan was prompted by the Sandiganbayan decision handed down early Saturday that house arrest is not authorized by law and the Rules of Court, and is in violation of the Constitution.
Zubiri said the disgraced presidents allies may explore the Charter change (Cha-cha) option, "but that is a long shot."
He said the ousted leader may rot in jail waiting for something that may never come.
"A Cha-cha is not in this administrations agenda," he said.
The Lakas congressman recalled that Malacañang doused cold water last week on renewed proposals by some congressmen that the Charter be revised.
Palace officials said the government has more important things to do than promote rewriting of the Constitution.
Following Saturdays Sandigan decision, some congressmen urged President Arroyo and the Philippine National Police to return Estrada and son Jinggoy to the Fort Sto. Domingo bungalow that the administration had built for him in Sta. Rosa, Laguna.
They said father and son have been staying at the Veterans Memorial Hospital in Quezon City for several weeks now, and there is no more reason for them to stay any longer there.
Upon the Presidents orders, Army engineers had started the construction of "mansion-like" quarters inside the hospital compound, but Mrs. Arroyo stopped the job after her civil society supporters threatened to launch massive protests.