Hillary Clinton's latest ad campaign features an architect who claims Donald Trump almost put his firm out of business.

"Donald Trump hired my small business to design a clubhouse for the Trump National Golf Club," states Andrew Tesoro of Andrew Tesoro Architects. The ad intersperses Tesoro's account of working for Trump with video clips of the Republican presidential candidate espousing his business acumen.

"I sent a bill. It wasn’t paid," states Tesoro, who accuses Trump Organization representatives of "bullying" him into accepting a significantly reduced fee – just over a third of what the firm had billed.

"I didn’t feel that I had a lot of choice but to accept their low-ball offer. I had already paid out that money. That was money gone. That was just absorbed by me personally," Tesoro says.

The firm then sent that invoice. "And it wasn't paid."

Tesoro recounts visiting Trump, who said, "I really don’t think I should pay any more because I spent too much on this building.”

After deciding that a prolonged legal battle would be too expensive, Tesoro accepted half of the already reduced fee.

"It almost put me out of business," Tesoro continues. "We had to max out the credit lines to keep the little ship afloat and pay the rent, and I made virtually zero money for a couple of years, and lived on meager savings that were supposed to be for my son to go to school to keep from folding."

“You can’t run a country the way Mr. Trump has run his businesses," Tesoro concludes.

The ad continues a line of attack against Trump's business record that Clinton has been employing more and more frequently in the last few weeks. Watch the full ad here:

As a major developer, Trump has had more encounters with architects than your average presidential candidate. Find out more: