In a strongly worded letter to Chief Dean Esserman this week, the New Haven Police Department union condemned the chief’s leadership.

The union called Esserman a bully and said his “outright boorish” leadership has sunk department morale and spurred an exodus of officers in a letter written by NHPD Officer Lloyd Barrett, an executive board member of police Local 530, on behalf of the entire union executive board, the New Haven Register reported.

“I am appalled of the actions you have taken since you have become the Chief of Police in the City of New Haven,” Barrett wrote in his letter, sent to Esserman and posted at the department for the rank and file. “Since your arrival several officers have chosen to retire or resign rather than deal with your demeanor towards these respected officers.”

Since Esserman arrived as chief in November 2011, he has made sweeping changes to the department’s personnel and management, in line with a community policing strategy that seeks to improve the relationship between the police and the public.

The NHPD union leadership has faced criticism in recent months for not raising the concerns of the rank and file with Esserman, the Register reported. NHPD union president Arpad Tolnay told the News in April he was adopting a “wait-and-see” approach to asses Esserman’s leadership.

But the union’s “diplomatic and soft-spoken” approach was not successful, Tolnay told the Register, prompting Barrett’s letter to the chief.

This is not the first time the NHPD’s union has pushed back against department leadership. Last February, the union voted no-confidence in then-NHPD Chief Frank Limon in a landslide 246-21 ballot. And in his letter, Barrett referred to the “acrimonious labor era” under Chief Nick Pastore in the early 1990s.

When Esserman was sworn in, he became the city’s fourth chief in four years. His contract runs until Feb. 1, 2014.