The disputed bill relates to services provided since 2019, including early representation in some of the notorious election rigging cases, NBC News reports.

Robert Costello and law firm Davidoff Hutcher & Citron say they have been forced to resort to the New York Supreme Court as Giuliani paid only $214,000 of a bill of over $1.5 million.

The lawsuit exposes a remarkable rift between Costello and Giuliani, who have had a long and close association since working together as prosecutors in New York in the 1970s, according to The Guardian.

In a statement, Giuliani said: “I can’t express how personally hurt I am by what Bob Costello has done. It’s a real shame when lawyers do things like this, and all I will say is that their bill is way in excess to anything approaching legitimate fees.”

Giuilani’s long legal career is in tatters as a result of his association with Trump and his baseless lawsuits aimed at overturning the result of the 2020 presidential election, which he lost.

He was suspended from legal practice in New York in 2021 and a disciplinary panel this summer recommended he be barred in Washington D.C. as well.