Calderon's ruling National Action Party (PAN) will have 52 seats in the senate, more than other parties but still short of a majority, the electoral court said on Wednesday.

The Institutional Revolutionary Party (PRI), which ruled Mexico for most of the last century, will have 33 seats in the senate, and Andres Manuel Lopez Obrador's Party of the Democratic Revolution (PRD) will have 28 seats.

The PAN will have 206 seats in the lower house, with 123 controlled by the PRD and 105 held by the PRI.

Open defiance

Supporters of Lopez Obrador said their once-peaceful protest movement would become openly defiant of Mexican law if a full recount is not ordered in the disputed presidential race.

Lopez Obrador supporters have
been protesting in the capital

The electoral judges must declare a president elect by September 6.

Lopez Obrador lost the presidential vote on July 2 by a hair and his PRD has challenged the result, alleging fraud.

His party had also contested some of the results of the congressional election.

For more than two weeks, Lopez Obrador's supporters have protested against the election result by camping out in Mexico City's giant Zocalo square, the symbolic centre of political power in Mexico, and along the city's central Reforma Avenue.

Lopez Obrador supporters, backed by the city government, have already seized main streets in the heart of the capital, setting up protest camps on the elegant Reforma Avenue and clashing with federal police outside congress.

Gerardo Fernandez, an aide to Lopez Obrador, refused to say what illegal acts supporters were planning. But he told reporters on Wednesday that the campaign of civil disobedience would begin after a mass meeting on September 16 and will "imply a position of rebellion against authorities".

"The right is trying to impose a president, and we are not going to let this happen," Fernandez said.

No violence pledge

He said the movement would not include an "armed insurgency".

But riot police and demonstrators clashed in Mexico City as protests against the results of the presidential elections turned violent on Monday.

PDR supporters threw rocks at police, who employed baton charges and tear gas. At least eight demonstrators were injured.

Calderon's campaign says the election was clean and has criticised protesters for "kidnapping" the capital.

With tensions rising in the capital, more than 1,000 federal police officers in body armour have encircled congress with steel barriers and armoured vehicles, prompting the Mexico City authorities to accuse the government of authoritarianism.