New York City firefighters, who worked side-by-side with former Mayor Rudy Giuliani (R) during the chaos of the Sept. 11, 2001, terrorist attacks and its drawn-out, somber aftermath, consider Giuliani anything but a hero.

And the enmity that has built up between Giuliani and the Big Apple’s firefighters in the intervening five and a half years threatens to cast a pall over the former mayor’s presidential ambitions, which are built in large part on the heroic image of his performance following the terrorist attacks.

Late last month, International Association of Fire Fighters President Harold Schaitberger and four IAFF leaders from New York drafted a letter to members of the union informing them that Giuliani would not be invited to the IAFF’s forum for presidential candidates on March 14 in Washington, D.C.

The letter — which was never sent — accuses Giuliani of showing “a disgraceful lack of respect” for the firefighters who died in the World Trade Center on 9/11 and their colleagues who continued to search for them in the aftermath of the towers’ collapse.

Eventually Giuliani was invited to the candidate forum. According to sources, he first declined to attend, then agreed, but now has pulled out again.

It is not clear whether Giuliani’s reluctance to appear at the forum has anything to do with IAFF letter, which was first leaked to Newsday and was first reported this afternoon on a blog published by the newspaper.

The three-page letter lists a withering set of grievances about Giuliani’s in the weeks following the terrorist strikes.

According to the letter, which the union sent to other media outlets after Newsday obtained a copy, Giuliani limited the number of firefighters who could search for the remains of first responders and others who had been killed in the towers once tens of millions of dollars’ worth of assets from the Bank of Nova Scotia that had been buried beneath the rubble were finally recovered. Instead, he authorized a “scoop and dump” operation to expedite the clean-up of Ground Zero.

“Mayor Giuliani’s actions meant that firefighters and citizens who perished would either remain buried at Ground Zero forever, with no closure for families, or be removed like garbage and deposited at the Fresh Kills Landfill” (the primary dumping ground for solid waste in New York City), the union officials wrote.

Giuliani’s campaign did not directly respond to the union’s charges, but did release a statement from the executive director of Firefighters for Rudy describing the volume of support his White House campaign has received from “first responders from across the country.”

The union’s letter was hardly the first criticism lobbed at Giuliani by firefighters since the terrorist strikes. His administration at City Hall has been accused of furnishing firefighters with antiquated, inoperable emergency radios that largely did not work on Sept. 11, and of allowing firefighters and other emergency workers to work without wearing respirators, which could have prevented them from being exposed to toxic materials.

In a separate development, Giuliani this week snagged the support of Rep. Jim Walsh (R-N.Y.), who becomes the ninth Member of Congress to back the former mayor’s presidential bid.