Mayor Bill de Blasio pushed back on predecessor Rudy Giuliani's op-ed suggesting de Blasio's progressive agenda worsened the New York City's homelessness problem.

"I think he’s delusional," de Blasio said of Giuliani on Monday. "Homelessness went up about 40 percent on his watch."

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The mayoral spat comes on the heels of Giuliani's latest attack on de Blasio's homelessness agenda via a New York Post editorial in which he never address the sitting mayor by name and recalls his own policies.

"People living on the street, urinating and defecating there, marked the Dark Ages of Western civilization," Giulani wrote, adding that his administration developed "humane and effective solutions."

He earlier told NBC New York the solution to addressing the homeless was to "chase 'em and you chase 'em and you chase 'em and you chase 'em, and they either get the treatment that they need or you chase 'em out of the city."

De Blasio noted the change in rhetoric.

"This is really a tale of two Rudys," he said. "One who says he liked to chase people away and another who suddenly thinks he was nurturing to them."

In December, the de Blasio administration recognized an all-time high of more than 60,000 homeless adults and children in emergency shelters.