Manchester City Council will this week join a network of public and private bodies across the city and the world to mark International Day Against Homophobia.
International Day Against Homophobia ( Idaho ) is marked on 17 May each year - the anniversary of the day, in 1990, when the World Health Organisation removed homosexuality from its list of mental disorders.
To mark Idaho , the council will fly the rainbow flag - the international symbol of gay pride - from the Town Hall.
Incoming Council spokesperson on gay men's issues, Councillor Kevin Peel, said: " Manchester has led the way both in the UK and the world on lesbian, gay, bisexual and trans rights and it's right that we mark Idaho by proudly flying the rainbow flag.
"There are still dozens of countries across the world where it is illegal to be gay. Men and women can be put into prison and even put to death - just because of their sexuality. It's disgraceful. By flying the flag we are sending out a beacon of tolerance across the world and telling all those who suffer under oppressive regimes that there is hope."
Incoming Council spokesperson on lesbian issues, Councillor Bev Craig, added: "It's almost unbelievable that little more than 20 years ago the WHO still considered homosexuality to be a mental disorder, and it shows that there is still so much to do.
"As well as sending out a message to the world, Idaho is a way of us telling Manchester people that we take homophobia seriously. Although we have made great strides towards equality, homophobia is still very real for people across our city. This is our way of saying to people who experience it that we stand with them and against those who try and drag us backwards."
Idaho was first marked in 2005 and is now recognised in more than 50 countries around the world.
Last year, more than 250 rainbow flags flew across Greater Manchester to mark Idaho and it is hoped that even more companies, organisations and individuals will do so this year.
If you are struggling with your sexuality, there are a range of organisations across the city who can provide help, support and advice. For more information visit the Lesbian and Gay Foundation's website at http://www.lgf.org.uk/. The LGF also operates a helpline on 08453 303030. Calls are charged at local rates and lines are open between 10am and 10pm daily.
Victims of homophobic hate crime can report it by calling the police on 101 or online at http://www.gmp.police.uk/hatecrime. In an emergency, always dial 999.