Police Chief John Beaudette “physically” bumped the department’s senior lieutenant during an angry confrontation over patrolmen assignments, a union attorney said in a letter to Mayor John Bell.

The confrontation between Beaudette and Lt. Jerris Cook happened Aug. 31 in the watch commander’s office at the police station, according to the union, and was reported to the Gloucester Superior Officers Association by Cook last week. The association represents the department’s 13 lieutenants and sergeants.

“Chief Beaudette’s behavior in this incident is clearly unacceptable and has no place in a professional, paramilitary setting,” the letter to Bell said. At one point, the letter said, Beaudette was “physically bumping into Lt. Cook, at which point Lt. Cook asked, ‘Are you bumping me?’ to which Chief Beaudette responded, ‘I just have a big belly.’”

The complaint is the latest in a string of grievances and other disputes between the city’s police unions and the chief and mayor.

The Sept. 7 letter from attorney John Becker of the Boston firm Sandulli Grace suggested the incident might have been in retaliation for union grievances filed against Beaudette’s policies. The letter also said Cook may consult

a private lawyer about his legal

options.

Cook is normally assigned as watch commander for the 4 p.m. to midnight shift. On Aug. 31, he swapped with Lt. Thomas Williams, who works the 8 a.m. to 4 p.m. shift. Cook also made two changes on the roster, moving Patrolman William Cahill’s beat from the northern part of Gloucester to West Gloucester, where Cahill lives, and Patrolman Jeremiah Nicastro to the northern section because he lives in Lanesville and knows its people better.

“Shortly after these changes were made, Chief Beaudette stormed into the watch commander’s office, where Lt. Cook was stationed,” the letter stated. “Chief Beaudette, obviously agitated, confronted Lt. Cook about the assignment changes.”

Beaudette stood 2 inches from Cook and told the lieutenant he was starting trouble, the letter continued.

“Lt. Cook asked Chief Beaudette if he was threatening him, to which Chief Beaudette repeated, ‘The gloves are off,’” the letter said.

Becker wrote that Cook and the superior officers union believe Beaudette’s reaction created “a physically and verbally threatening encounter.”

A call left on Becker’s voicemail yesterday morning seeking comment was not returned.

Beaudette said yesterday he could not comment on the letter, although he said he is aware of it. “Everything’s going to be an internal matter,” he said.

Becker wrote in the letter that he will “examine any legal redress that (the union) may have in this matter, and I understand that Lt. Cook is also contemplating consulting with a private attorney.”

Yesterday, Cook said only that he is “disappointed” in the way the confrontation unfolded.

Sgt. John McCarthy, president of the Superior Officers Association, said the union hopes for an “amicable resolution.”

“The statements that were made, we consider threatening, and when you say, ‘The gloves are off,’ you don’t know what will happen next,” McCarthy said.

Bell’s office received the letter Sept. 10. Steven Magoon, Bell’s chief of staff, said yesterday the mayor will review the letter and decide how to respond.

The superior officers union had filed two grievances in the past over decisions Beaudette made restricting shift-swapping and limiting operational decisions that watch commanders can make. The letter stated that “any adverse actions taken in retaliation for these grievances would be illegal under ... Mass. General Laws.”

Beaudette’s tenure has been marked by discord.

An 18-month incomplete investigation of a patrolman, Stephen Lamberis Jr., resulted in Lamberis’ return to work in January after a paid leave that cost the city close to $175,000 in salary, benefits and overtime pay to fill his shifts.

The details of that investigation have not been released, except that Beaudette believed Lamberis violated three department policies at the end of July and beginning of August in 2005. Lamberis was put on paid administrative leave Aug. 11, 2005. A five-day suspension was ordered that October and overturned weeks later.

The Gloucester Police Patrolman’s Association publicly accused Beaudette at a City Council meeting March 30 of dividing the force into two camps — favorites who get easy, lucrative overtime, and others who are subjected to harsh training meted out as punishment. The union cited an outdoor firearms training session during blizzard-like conditions the previous Friday night as one example of punishment.

As a lieutenant before his promotion to chief two years ago, Beaudette was the department’s training director.

Bell himself has been accused of favoritism for his decision not to promote McCarthy to lieutenant in 2005. McCarthy sued in federal court Dec. 9, 2005, claiming Bell violated his First Amendment rights by not promoting him in retaliation for his union activities.

The city and McCarthy entered mediation in April, following a scheduled trial date for that month.

An agreement signed by Beaudette and Bell on June 27 and by McCarthy on July 12 will give McCarthy two lump sums totalling $70,000 and will pay him as a lieutenant — $62,735 annually — when he is on duty from Jan. 1, 2007 to Jan. 1, 2009. A sergeant’s salary is $56,003. The agreement also promised McCarthy the next vacant lieutenant’s position.

Not counting Beaudette, there are 13 superior officers and 47 patrolmen. The department’s 2007 budget is $4.5 million.