Rival deputies scuffled on the floor of Mexico's Congress on Tuesday (November 28) as leftist lawmakers tried to take the podium to protest President-elect Felipe Calderon's inauguration this week. Leftists from the Party of the Democratic Revolution, who say Calderon won July's presidential election by fraud, have vowed to prevent the conservative from being sworn in at a ceremony in Congress on Friday (December 1). "We didn't attempt to use any violence, but PAN lawmakers tried to block the way to the tribunal," PRD Congressman Javier Hernandez Manzanares said. The leftists and lawmakers from Calderon's National Action Party pushed and shouted at each other in the chamber of deputies. The speaker of the chamber, Jorge Zermeno, suspended the session. "This is a sad day for Congress. We have two parliamentary fractions that can't agree to make the congress of the union work like the Constitution dictates," lamented PRI congressman Juan Manuel Paras Gonzales. Mexico has been divided politically since the election, which Calderon won by less than one percentage point. But Tuesday's exchange of punches was yet unprecedented. "Our intention simply was to stop the PRD from taking over the tribunal. We got a heads up that they were planning on doing so and we considered appropriate to tell them to stop peacefully once and for all," claimed president-elect party congressman, Francisco Fraile. Losing candidate Andres Manuel Lopez Obrador has declared himself Mexico's "legitimate president" and vows to hound Calderon, a former energy minister in outgoing President Vicente Fox's government.