President Vicente Fox was forced to forego his final state-of-the-nation address Friday after leftist lawmakers stormed the stage of Congress to protest disputed July 2 elections.

Instead, he gave his speech on television, and called on Mexico to mend deep divisions that he said threaten the nation's newfound democracy.

It was the first time in modern Mexican history a president hasn't given the annual address to Congress. Fox arrived at the door of the Legislative Palace, handed in a written copy — as the constitution requires — and announced over the loudspeaker that he wouldn't appear before lawmakers. He did not enter the chambers, and Congress was adjourned.

CountryWatch: Mexico

Appearing on television later as thousands of protesters occupied Mexico City's center, Fox said the nation "requires harmony, not anarchy."

"Whoever attacks our laws and institutions also attacks our history and Mexico," he said, a thinly veiled reference to leftist presidential candidate Andres Manuel Lopez Obrador.

He criticized lawmakers' actions as "contrary to democratic practices" and said: "A divided society is a weak society, a society that is incapable of achieving its goals or taking care of its neediest members."

The opposition lawmakers took over the stage in Congress shortly before Fox arrived, shouting "Vote by Vote" — a rallying cry for Lopez Obrador's bid for a full recount in the election.

The former Mexico City mayor says Fox robbed him of his victory, using fraud and backroom deals. Fox denies that.

The standoff came six days before the top electoral court must declare a president-elect or annul the July 2 vote and order a new election. So far, rulings have favored ruling party candidate Felipe Calderon, who was ahead by about 240,000 votes in the official count.

Lopez Obrador has already said he won't recognize the electoral court's decision, and he plans to create a parallel government and rule from the streets.

Fearing violent protests, authorities earlier surrounded Congress for up to 10 blocks with multiple layers of steel barriers; attack dogs in cages, ready to be released; water cannons; and riot police in full protective gear. Entire neighborhoods were sealed off, preventing some of the city's sprawling markets from opening, and nearby subway stations were shut down.

Police used mirrors and dogs to inspect cars for explosives before allowing them to pass, and opposition lawmakers said police even tried to prevent them from arriving despite their credentials. Some said they were pushed and shoved by authorities.

"It's completely militarized around here. It is completely illegal, unconstitutional," Democratic Revolution congressman Cuauhtemoc Sandoval told The Associated Press. "Vicente Fox started out as a president, and is finishing up as a dictator."

Many had feared the deepening political turmoil over the election to replace Fox could explode into violence, but Lopez Obrador called on his supporters to remain peacefully gathered in Mexico City's Zocalo plaza — instead of marching on Congress as they had previously planned.

"We aren't going to fall into any trap. We aren't going to be provoked," he told tens of thousands who waited in a driving rain to hear him speak.

Several hundred protesters marched within a few blocks of Congress, throwing rocks at riot police. But there were no major clashes.

The tense situation was a far cry from the optimism and enthusiasm that followed Fox's victory six years ago. That election ended 71 years of one-party rule and prompted the world to declare Mexico a true democracy.

Protesters said they were ready to do whatever it takes to support Lopez Obrador. Fernando Calles, a 26-year-old university professor, said he was ready to fight for the former Mexico City mayor "until the death, until the final consequences."

"We lived 500 years of repression, and now we represent the new face of Mexico," he said.

The tight election left the nation deeply divided, with Lopez Obrador — who portrayed himself as a champion of the poor — alleging that fraud accounted for an official count showing him 0.6 percent behind Calderon.

Fox, a former Coca-Cola executive, ushered in economic stability and brought inflation to record lows, but he has been unable to secure a migration accord with the U.S. or significantly reduce poverty.