It’s not a party until someone announces a run for mayor.

Pittsburgh City Councilman Bill Peduto officially declared his plans to run for mayor of Pittsburgh during his annual holiday party and fundraiser Thursday night at the Crucible Building, a converted factory in the Strip District.

“Tonight I am announcing my campaign for mayor,” Peduto said, as the black velvet curtain behind him dropped in dramatic fashion to unveil a poster with yellow bridges and Pittsburgh’s skyline that read, “Peduto Democrat for Mayor.”

Peduto, 48, of Point Breeze will face off against Mayor Luke Ravenstahl, who assumed office in 2006, and Pittsburgh Controller Michael Lamb in the Democratic primary on May 21. Neither Ravenstahl nor Lamb have officially declared their candidacies, but both have voiced their intentions to run.

In Pittsburgh, the Democratic primary election has decided the mayor every election since 1933.

Peduto gave the hundreds of party-goers a taste of his plans for Pittsburgh during his announcement. He emphasized the importance of creating connections between different organizations that govern Pittsburgh and between city government and Pittsburghers.

“It’s all about building bridges,” Peduto said. “We need to break the shackles of the old rusty political machine. It’s not about politics, it’s about people.”

Peduto’s announcement arrived after months of suspicion that he would run. On Sept. 27, Peduto filed the necessary paperwork to run for mayor and begin fundraising.

“The worst kept secret in politics is now released,” Peduto joked after his speech.

At least a dozen Pitt students were on hand to hear Peduto’s announcement.

Junior Robert Beecher said he attended the event because of his strong support for Peduto’s candidacy.

“His views on regionalism and his views on the way to leverage the assets of the greater Pittsburgh community have impressed me ever since I stepped on campus,” he said.

Senior Kevin Kerr believes Peduto would prove to be a strong mayor for college students.

“He’s represented a lot of students in his role as a councilman, and he’s done a lot for them. He’s one of the people who is thinking progressively and about the future,” Kerr said.

In his current position as councilman for Pittsburgh’s 8th district, which he’s been in for 12 years, Peduto represents Pittsburgh’s East End, an area that includes the neighborhoods of Bloomfield, Oakland, Shadyside, Squirrel Hill, East Liberty and Point Breeze.

Several members of the Pitt Democrats club attended the event to learn about Peduto so that they can compare him with the other candidates and make an informed decision come May.

We’re excited for the mayoral primary,” incoming Pitt Democrats business manager Zach Gozlan said. “It’s an inter-democratic race which is really unique for us.”

Attorney County Executive Rich Fitzgerald introduced Peduto at the event, giving the councilman his first endorsement.

“I‘m proud to be here tonight to endorse and proudly proclaim that I am supporting Bill Peduto as the next mayor of the city of Pittsburgh,” he said.

Fitzgerald said that over the course of 12 years working with Peduto, he “came to see Bill’s work effort, seriousness, and love for the region.”

Fitzgerald was the first donor to Peduto’s campaign in September, contributing $8,000, the maximum allowable under the Pittsburgh’s campaign finance law to the campaign effort.

Peduto previously ran for mayor in both 2005 and 2007 Democratic primaries. Bob O’ Connor defeated Peduto in 2005 and Peduto dropped out of the 2007 election early, after polls indicated that Ravenstahl held a strong advantage.

When asked about his failed 2005 run, Peduto emphasized the greater financial strength of his campaign this time around. He noted that the holiday party fundraiser alone raised around $250,000, the total amount his campaigned earned in 2005.

“If you can’t ante up one million dollars, you can’t be in the race,” Peduto said.

Peduto counted a larger volunteer and support base as another difference between this year’s campaign and his previous runs at the mayoral office.

Peduto revealed in late November that he will not seek re-election to his seat on city council, a move he described as removing the “net” from beneath his effort to run for mayor.

“There comes a time when you’ve done what you sought to do. I did that on city council. Now I’m ready to do that in the mayor’s office,” Peduto said.