BOSTON (AP) Construction vehicles rolled onto the site of next month’s Democratic National Convention on Friday after protesting police officers took their fight from the sports arena, where they had blocked work for three days, to City Hall.

Marching through streets cordoned off by their uniformed brethren, about 300 police officers and other union allies shouted "Tom-my, Tom-my" in a taunting challenge to Boston Mayor Thomas Menino, with whom they’ve been locked in a bitter contract dispute.

The protesting ended a day after a judge sent federal marshals to the site to ensure that the union demonstrators were not blocking access to construction crews who are converting the FleetCenter arena into a staging ground for John Kerry’s nomination.

Since last Tuesday, when the $14 million renovation project was scheduled to begin, angry mobs of union members turned away cranes, cement trucks and construction workers who refused to cross picket lines.

Union leaders said they were not backing down but simply moving their fight to other venues because of what they contend is an infringement of their First Amendment rights to protest.

"I don’t need no stinkin’ marshals in my town," said Thomas Nee, president of the Boston Police Patrolmen’s Association, which has been without a contract for nearly two years. "We have been essentially denied our constitutional privileges by a United States federal court judge."

While the standoff with the police continues, Menino reached a tentative agreement with four of the 11 bargaining units represented by the Service Employees International Union Local 888, the largest city union that remains without a contract.

Democratic strategists have said that it is key for the city to reach agreements with SEIU and the firefighters union, which could peel their support from the more militant police union. The union, which has endorsed several Republicans in the past, has a history of generating headlines with its protests.

The three-day standoff took its toll on the Democratic National Committee, likely driving up costs by as much as $100,000 for each day of lost work and forcing organizers to reschedule a media. The national media will visit the site June 29.

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