Mayor Bill de Blasio fired back at a high-profile campaign donor Saturday, denying the donor's testimony that that he received favorable treatment from City Hall.

"Jona Rechnitz has had his turn. Now it's my turn to tell you the truth. Jona Rechnitz is a liar and a felon — it's as simple as that," de Blasio said at an impromptu news conference in Brooklyn. "He is a convicted criminal. To save his own skin, he has lied about a number of things, including access to government officials. He has lied about the integrity of my administration. He has lied about exchanges with me."

Rechnitz donated more than $100,000 to de Blasio's campaigns and causes over the years, and he said his donations bought him special access to City Hall.

He has been the star witness for the prosecution in the corruption trial of the former head of the correction officers union, Norman Seabrook.

Rechnitz said he had the mayor's personal phone number, but de Blasio told reporters he has given his number out to thousands of people over the years, and only met and spoke with Rechnitz a handful of times.

De Blasio said he will not make public every meeting he had with Rechnitz.

The mayor would not comment when he was asked if the U.S. attorney should peruse perjury charges.

Defiant and defensive, de Blasio dismissed Rechnitz's testimony. He said the issues have been exhausted, as the federal investigation into his fundraising ended with no charges.

De Blasio's Republican rival, Staten Island Assemblywoman Nicole Malliotakis, kept her campaign events and seized on the entire issue.

"This is a legitimate witness because the prosecution has brought him in to testify under oath," Malliotakis said. "What's coming out during this trial is that there is an inappropriate relationship — like so many others — between donors and Bill de Blasio. City Hall is for sale right now, and we need to end it and give it back to the people."

Something voters will have to decide in less than two weeks.