Thousands of people in Mexico City have protested against a government proposal to legalize same-sex marriages, which they say would undermine traditional families.
Organisers said while they were not opposed to gay or lesbian rights, they want to defend family values and the institution of marriage.
The demonstrators have called for a meeting with President Enrique Pena Nieto to debate the issue.
Mexico is a predominantly Roman Catholic nation, where public opinion has been divided since May, when Mr Pena Nieto announced plans to change the constitution.
Same-sex marriages are legal in some Mexican states, but Mr Pena Nieto wants it to be allowed across the country.
Last year the supreme court declared that a ban on such unions imposed in many of Mexico’s states was unconstitutional however, many state legislatures have not changed their statutes to comply.