Striking Broadway stagehands accused theater owners and producers this afternoon of provoking the walkout that shut down 27 productions in order to unilaterally impose new work rules that would lead to unsafe conditions in theaters.

Saying that the owners and producers were insulting workers by exaggerating their incomes and using terms like "featherbedding" in describing staffing levels, James J. Claffey Jr., the president of Local One of the International Alliance of Theatrical Stage Employees, said no new talks would be scheduled until managers treat workers with respect.

His statement appeared to represent a hardening of attitude on the part of the union, which had never before struck in its 121-year history. Mr. Claffey said at a news conference in Manhattan that if the management proposals that were on the table when the talks broke off are still there at the next negotiation meeting, "we won't go back."

"We are being attacked," Mr. Claffey said of the management proposals. "We worked for months to make a deal," he said "We truly regret that there is no show."

The leaders of the musicians and actors union said they stood behind the stagehands against what Mr. Claffey said was an effort to reduce the middle-classstatus of theatrical workers.

He said the increasingly elaborate theatrical productions on Broadway had added to the burden of stagehands because they used larger, heavier scenery and equipment. The manning levels in previous agreements, which have been criticized as excessive, "is for our protection."

"If there is a four-person piece that needs to be moved, they want you to do it with three," Mr. Claffey said of the producers and theater owners.

In response, Charlotte St. Martin, executive director of the League of American Theaters and Producers, said the stagehands union "refused to budge on nearly every issue, protecting wasteful, costly and indefensible rules that are embedded like dead weights in contracts so obscure and old that no one truly remembers how, when or why they were introduced."

"We have the highest regard and respect for our stagehands," she said in a statement. "But they are not, as the union leadership characterizes them, the typical 'little guys' as far as compensation is concerned."

Ms. St. Martin added that the theater industry did not "want to be compelled to hire more workers than needed and pay them when there is no work for them to do."

Mr. Claffey of Local One said that Mayor Michael R. Bloomberg had been in touch with union officials to offer his help with the negotiations, but that they had "respectfully declined" his offer.