Thousands upon thousands of people, many sporting colourful Carnivale costumes and waving rainbow-coloured flags, marched in celebration of gay pride as well as calling for civil unions between gay people to be legalised.

“There have never been so many people at the Gay Pride Parade,” said Pedro Almeida, a spokesman for the gay, lesbian, bisexual and transgender group that organized the parade.

“This shows true support for our cause, that of civil unions of people of the same sex,” he said, speaking to AFP.

“With this many people showing up, the parade is a major step to strike [against] people’s prejudice against gays everywhere,” he said.

The event is Sao Paulo’s biggest tourist attraction, reportedly attracting 700,000 people from around the world this year.

The first such parade in 1997 drew 2,000 people, which grew to 1.5 million last year.

Thousands of gay and heterosexual couples danced down the main streets of Sao Paulo carrying giant rainbow flags, accompanied by floats blasting music from giant loudspeakers.

Civil unions between same-sex couples are only permitted in Brazil’s southernmost state of Rio Grande do Sul.

Gay activists are hoping that the government of President Luiz Inacio Lula da Silva will initiate a bill to legalise gay unions countrywide.

A campaign was launched during the parade to gather the 1.2 million signatures needed on a petition to force Congress to vote on the law, which will continue through to November.

Activists also want to bring to attention the rising problem of violence against gays, from gay bashing to murder.

“A homosexual is murdered here every two days — just for being homosexual,” said Mr Almeida.

Several other gay pride events will take place throughout Brazil in June.

Brazil is the world’s largest Roman Catholic nation, with the church steadfastly opposed to gay marriage.

Sao Paolo is Brazil’s gay epicentre.