Riga - As cold European air gives way to a warmer front, the season of eastern European gay pride parades is at hand to remind authorities of tolerance toward sexual minorities.

Groups in Latvia and Poland received permission to stage Gay Pride parades in their respective capitals, arguing that it's their right under European Union law. In Moscow, however, the city authorities denied a pro-gay group a permit to march on Saturday for the third year in a row.

In the past, gay pride has prompted savage backlashes in the three countries, with marches banned by the authorities and attacked by religious extremists, ultra-nationalists and communists.

In 2005 and 2006, pro-gay activists in Riga were attacked by anti- gay demonstrators who pelted them with eggs, fruit and excrement.

In 2007, several hundred police, including heavily-armoured riot squads, formed a human barrier at the Vermanes park in central Riga as up to 500 gay activists staged a peaceful "March for Equality" inside.

In Moscow, organizers have appealed to Russian President Dmitry Medvedev to override the city administration's ban on the parade.

Up to 100 volunteers from Amnesty International's British and Scandinavian groups are set to attend events in Latvia on Saturday, AI researcher Anders Dahlbeck said.

Latvia's failure to protect sexual minorities "has been very concerning, and we believe our presence at the march will ensure that the Latvian authorities feel obliged to protect the march, including both Latvian and international participants," he told Deutsche Presse-Agentur dpa.

Members of the Danish parliament also plan to act as observers.

"I hope our being there will give the right signal to the troublemakers," the Danish Social Democrat Flemmin Moeller Mortensen told a Danish radio station this week.

The troublemakers are mostly church leaders and politicians that frequently accuse gay activists of being paedophiles, perverts, criminals, drug addicts and sick.

"I don't think we should allow a small percentage of society to spread their perversion. Otherwise, we will have to give equal rights to other groups of people with sexual deviances," the Latvian capital's Deputy Mayor Andris Argalis told LETA news agency Wednesday.

Riga's Roman Catholic archbishop, Janis Pujats, issued a letter this week condemning the parade as "unlawful," saying it is immoral. The archbishop condemned homosexuality as going "against the natural order and therefore again the laws of God."

Tensions in predominantly Catholic Poland appeared to have abated after the country's right-wing government lost elections last year, but they didn't disappear.

Pro-gay groups and Amnesty International say discrimination based on sexual orientation persists. Warsaw's gay pride march is planned for July 7.

In the Baltics, homosexuality was outlawed throughout the Soviet occupation. It was decriminalized only after independence in 1991, but public attitudes have been slow to change. (dpa)