The largest pride parade in central and Eastern Europe was expected to bring thousands of people to the streets of Warsaw on Saturday, at a time when the gay rights movement in Poland is under siege by hate speech and a government campaign depicting it as a threat to families and society. Diplomats from Canada, the United States and other Western nations will continue a tradition of joining the Equality Parade to show their support for what is considered a basic human right in many places. Warsaw’s mayor, Rafal Trzaskowski, was expected to join the parade for the first time. While many Poles in Warsaw and other cities have grown increasingly supportive of the rights of lesbians, gay men, and bisexual and transgender people, a backlash is underway. In recent months, officials from the right-wing governing party, Law and Justice, have portrayed the rights movement, particularly calls for sex education stressing tolerance, as a threat to families and children.