Over one million people attended Sao Paulo Pride on Sunday. The annual event is the world’s largest Pride event in Brazil’s largest city.

Marchers walked under a massive rainbow flag and carried banners with slogans like “Never going back in the closet”.

“We have got to make a change in the Constitution so that we are all citizens with the same rights,” said Culture Minister Marta Suplicy in a speech to the marchers.

Sao Paolo has celebrated Pride every year since 1997 with steadily growing numbers. Military police stopped releasing official figures six years ago, when pride-goers numbered two and a half million.

In 2011, event-goers in the southern hemisphere’s largest city numbered over 4 million, organisers said.

Numbers were diminished by bad weather this year, with unusual cold and heavy rains throughout.

“The parade is not an off-season carnival. It is a movement of massive visibility on part of a community which suffers daily prejudice and discrimination, violence, hatred and intolerance,” said Fernando Quaresma, president of the Association of LGBT Pride Parade in Sao Paulo.

In December 2012 Sao Paulo became the first state in Brazil to effectively legalise same-sex marriage.

Last month same-sex marriage was finally approved nationwide in a landmark ruling by the Brazilian National Council of Justice. However, Congress has yet to approve a law on same-sex marriage, as it is being blocked by religious factions.

“The legislature has not been fulfilling its role to pass a law to guarantee the end of social injustice,” said Quaresma. He added that “religious fundamentalists” in Congress were “attacking the secular state and the civil rights of lesbians, gays, bisexuals and transgender people.”

Although progressive in its moves towards equal marriage, Brazil remains a deeply Roman Catholic nation, and opposition to homosexuality is widespread.

In April, Catholic priest Roberto Francisco Daniel was excommunicated after he resigned his position in protest against the church’s opposition to gay rights.