But that´s the only clear piece of information in the increasingly complicated and potentially embarrassing scenario developing around the Dec. 1 ceremony.

The where, what and who of the traditional event were still in doubt 36 hours before it was to take place.

Party leaders on Wednesday were discussing a possible change of venue, as well as eliminating outgoing President Vicente Fox from participation.

Foreign Relations Secretary Ernesto Derbez also warned that the uncertain atmosphere could lead to cancellations from foreign dignitaries planning to attend.

On Wednesday, deputies from Calderón´s National Action Party (PAN) and the opposition Democratic Revolution Party (PRD) continued into a second day their competing occupations of the speakers platforms in the Chamber of Deputies - the planned site of Friday´s event.

The PAN deputies say they´re there to protect Calderón´s swearing-in ceremony, while the protesting PRD legislators say they´re there to prevent it.

Party leaders, meanwhile, were holding meetings with their legislators and with each other in hopes of finding a solution to the pending crisis.

One proposal was to move the ceremony out of the Chamber, either to another site within the Legislative Palace complex or an outside venue such as the National Auditorium.

Such a last-minute change has been firmly opposed by two key PAN members - Chamber of Deputies President Jorge Zermeño and Calderón himself. But the idea appeared to be gaining momentum as a way of neutralizing PRD threats to disrupt the proceedings.

Héctor Larios, coordinator of PAN deputies, pointedly did not rule out a change of venue, and even Zermeño said he was prepared to "seek solutions" wherever they may be found.

Senators and deputies from the Institutional Revolutionary Party (PRI), the third force in Congress, have been strong advocates of a site shift, and on Wednesday a key PRD leader indicated that moving the ceremony away from the Chamber floor would be enough for his party to call off its planned disruption.

"If we tried to say the oath of office won´t take place anywhere, we´d be crazy," said Javier González Garza, leader of the PRD deputies in the lower house. "And if they say that the oath must take place there (in the Chamber), then they´re crazy."

González Garza indicated that PRD legislators would not even attend, let alone disrupt, a joint session of Congress if it took place in the National Auditorium. That would leave it to the PAN, PRI and minor parties to fulfill the quorum requirement so the ceremony could take place legally.

The PRD and PRI also agree that Fox should stay away from the event, wherever it takes place. Legally, he will be an ex-president when the oath is given, Calderón having automatically assumed the presidency at the stroke of midnight. But the outgoing president traditionally presents the sash of office to the new one.

But official presidential spokesman Rubén Águilar said that Fox still has every intention of participating in the ceremony. "Wherever the session takes place, he´ll be there to deliver the presidential sash," Águilar said.