Mexico's left-wing presidential candidate Andres Manuel Lopez Obrador on Sunday called on his supporters to continue their demonstrations if his conservative rival is declared president by an electoral court.
The opposition leader told thousands of his supporters rallying at the Zocalo, the capital city's main square, that the protests could continue for years if the Electoral Tribunal, the country's top electoral court, ruled against him.
Obrador is challenging the official result of the country's July 2 election, which gave Felipe Calderon, candidate of the incumbent right-wing National Action Party (PAN), victory with a 0.58 percentage lead over Obrador.
Claiming massive fraud at polling stations across the country, the opposition candidate demands a vote-by-vote recount.
Terming the government as "illegal" and "illegitimate" if Calderon is declared president-elect, Obrador called on his supporters to demonstrate at the Legislative Palace on Sept. 1, when President Vicente Fox presents his final state of the nation address.
He also urged his supporters to meet on Sept. 6, the deadline the electoral court has to formally name a president-elect.
Obrador told his supporters that he also wanted to hold a National Democratic Convention on Sept. 16, which was aimed at forming a long-term anti-government movement.
The opposition's protests have blocked three of the capital's most important streets since two weeks ago.
The court has to settle all fraud claims arising from the election process before Aug. 31 and will make a final ruling on Sept. 6.
European Union observers said they had detected no major problems during the election.