Three candidates in the race for Congress in Brooklyn’s 11th district attacked David Yassky yesterday after the lawmaker abruptly canceled a fund-raiser with a controversial architect.

Mr. Yassky’s campaign had scheduled the event for Tuesday night with Robert Scarano Jr., a prominent architect who has been criticized in Brooklyn for building too big and who recently struck a deal with the city Buildings Department following an investigation into unsafe work practices. After word of the fund-raiser got out on Tuesday, Mr. Yassky called it off.

“Mr. Yassky is a political chicken,” a rival candidate in the race, Chris Owens, charged yesterday. “He has done this time and time again.” Citing Mr. Yassky’s recent criticism of the Atlantic Yards project, Mr. Owens said the City Council member frequently takes politically unpopular positions, only to change his mind. “He gets caught, and then he flip-flops.”

The Yassky campaign has said that it has not taken contributions from Mr. Scarano and that it cancelled the fund-raiser because the campaign “didn’t think it was appropriate.”

In a district where development often means controversy, Mr. Yassky has come under criticism for accepting money from developers. Mr. Scarano, an architect on many projects linked with Brooklyn’s construction boom, has won many honors for his designs, including a Brooklyn Icon Award presented by the borough’s president, Marty Markowitz. He has also faced criticism from opponents who say that his buildings are too large and that he circumvents zoning laws to maximize their size.

In a settlement with the city earlier this month, Mr. Scarano agreed to relinquish a license allowing him to certify his own designs. The city had investigated him for maintaining unsafe conditions after a construction worker was killed at one of his building sites in March. The agreement stipulated that it was not an admission of guilt or liability by Mr. Scarano.

Mr. Scarano did not respond to numerous messages left at his office yesterday.

A Yassky campaign source said a staffer in the finance department who did not know about Mr. Scarano scheduled the fund-raiser and that senior staff members canceled it when they found out. The source said the campaign has “hundreds” of workers and that events are frequently changed on the day they are supposed to occur.

Mr. Owens wasn’t buying that explanation. “It’s a convenient cover story,” he said. “Fund-raisers are not planned at the last minute. They are planned well in advance.”

The two other Democrats in the race, Council Member Yvette Clarke and state Senator Carl Andrews, also took shots at Mr. Yassky. “Robert Scarano has wreaked housing havoc all over south Park Slope and other parts of Brooklyn,” a Clarke spokesman, Stefan Friedman, said. “That David Yassky would agree to stand at a fund-raiser with this man — only to cancel at the last minute after the press got wind of it — speaks volumes about who Yassky prefers in the ongoing battle between developers and residents of the 11th district.”

An Andrews spokeswoman, Melissa DeRosa, said it was “just the latest example of a cozy relationship between David Yassky and big developers.”

A spokesman for Mr. Yassky, Evan Thies, declined to respond to the criticism.

Mr. Yassky and Ms. Clarke are considered front-runners in the close race, and the flap “is clearly something that could make a difference” in the Democratic primary on September 12, a Democratic political consultant not involved in the race, Scott Levenson, said.