NEW YORK — A weekend of St. Patrick’s Day revelry and tensions over the exclusion of gays in some of the celebrations culminated Monday in New York, where the world’s largest parade celebrating Irish heritage stepped off without the city’s new mayor and Guinness beer amid a dispute over whether participants can carry pro-gay signs.
Hundreds of thousands of spectators lined Fifth Avenue for the parade on a cold, gray day, but the crowd was only about half as thick as in previous years.
De Blasio held the traditional St. Patrick’s Day breakfast at Gracie Mansion with the Irish prime minister, Enda Kenny, but boycotted the parade because organizers said marchers were not allowed to carry gay-friendly signs or identify themselves as lesbian, gay, bisexual, or transgender. Kenny did join the procession.
Cardinal Timothy Dolan, who greeted passing dignitaries in front of St. Patrick’s Cathedral wearing a woolen Irish cap over his red cardinal’s skull cap, said he supports the participation of individual gays and hoped St. Patrick’s Day could be a day of unity and joy.
‘‘I know that there are thousands and thousands of gay people marching in this parade,’’ he said. ‘‘I know it. And I’m glad they are.’’
Police Commissioner William Bratton marched with a contingent of uniformed officers. Gay activists protesting the exclusion of official LGBT groups held a news conference before the march to say they did not think the city police should participate in uniform.
About two dozen gay rights advocates protested the parade holding placards high enough for marchers to see.
On Fifth Avenue, Richard Lynch joined the protest lineup. He said de Blasio should have ordered the police commissioner not to march.
Boston’s new mayor, Martin Walsh, opted out of that city’s parade Sunday after talks broke down that would have allowed a gay veterans group to march.
Guinness beer abruptly dropped its sponsorship of New York’s parade on Sunday over the controversy.
The Dublin-based company has pulled sponsorship assets, including on-air presence, parade participation, and any promotional materials that were not already printed, although the beer maker had already made a payment to parade organizers, spokeswoman Alix Dunn said.
Other beer companies earlier joined the boycotts, with Sam Adams withdrawing its sponsorship of Boston’s parade and Heineken following suit in New York. That leaves Ford as the last remaining major sponsor of the Manhattan parade.
De Blasio’s decision to skip the parade underscores lingering tensions over gay rights issues in the United States.
In refusing to be sidelined, Kenny said the holiday is about Irishness, not sexuality.
Kenny on Sunday became the first Irish prime minister to attend Boston’s annual St. Patrick’s Day breakfast. He has resisted pressure, in both Ireland and America, to support the demand of gay rights supporters to have equal rights to march in parades on St. Patrick’s Day.
De Blasio, in one of the first major events that Gracie Mansion has hosted under the new mayor, addressed several hundred people at the breakfast.
Sporting a green tie, de Blasio, who is not Irish, recalled his roots growing up in Massachusetts, living in the congressional district once represented by Irish-Americans John F. Kennedy and Thomas P. O’Neill, the late US House speaker.
He said in a toast that New York is a ‘‘city of immigrants’’ and residents ‘‘never forget’’ where they came from.
New York’s parade has drawn more than 1 million spectators and about 200,000 participants every March 17.