Evan Dobelle would have stepped down as president of Westfield State University in Massachusetts last week if trustees had agreed to let him take a paid sabbatical and return as a tenured professor in the fall, say several people briefed on the private negotiations.

But the trustees, alarmed at Dobelle’s free-spending and increasingly combative public remarks, placed him on paid leave instead, even making him turn in the keys to his university car at the end of the marathon Oct. 16 trustees meeting.

Now Dobelle, a former president of the University of Hawaii system who resigned in 2004 after facing similar allegations, has filed a federal lawsuit charging that trustees and the state’s top higher-education official have conspired to destroy his reputation, raising the stakes in a three-month-long leadership crisis that has rocked the state university. Lawyers hired by the trustees are already investigating Dobelle’s spending habits with plans to report their findings by Nov. 25.

"At age 68, Dr. Dobelle’s long-celebrated career has been swiftly, unjustly and perhaps irreparably damaged," reads Dobelle’s complaint, filed Thursday, which alleges that the investigation of his spending is part of a smear campaign to drive him from power at the 5,400-student university near Springfield.

Dobelle’s troubles at Westfield are similar to his controversial tenure at UH from 2001 to 2004. UH regents unanimously voted to fire him in 2004 amid charges of lavish spending, dishonesty and wasting university resources.

Dobelle said he was a victim of a vendetta by Hawaii Republican Gov. Linda Lingle, and he fought back with lawyers.

He threatened to sue UH for wrongful termination. The regents reached a settlement and Dobelle resigned.

Dobelle, who is described as a visionary five times in the lawsuit, blamed much of his trouble on Jack Flynn, a senior State Police official who became chairman of the trustees in July 2012.

Since then, Dobelle and his publicist say, Flynn has been out to undermine Dobelle so that he could turn Westfield State into a "diploma mill" for state troopers.

"Flynn’s mission of attacking Dr. Dobelle took place without regard to rules or laws specifically designed to avoid these types of cowboy tactics," the complaint says. Dobelle contended the investigation of his business expenses was just part of a "guerrilla war for control of the university."

Flynn did not respond to requests for comment, but he has denied any conspiracy against Dobelle. Westfield State officials have said there is no evidence to support Dobelle’s contention that the school was being turned into a diploma mill.

Flynn did hire an accounting firm to review Dobelle’s use of credit cards last year, including a $200,000 tab on one university-related card, without seeking approval of the 11-member board. But Flynn has said he was trying to handle the charges quietly because they were embarrassing.

A spokeswoman for Higher Education Commissioner Richard Freeland, who is named as a defendant, said she had not seen the lawsuit, "but it appears to be yet another distraction from the issue of whether state funds were used inappropriately, which is the only issue that matters here."

Freeland froze some state funding to Westfield State earlier this month, out of concern about Dobelle’s leadership.

For a time it looked as if the two sides might avoid further public bloodletting during the closed-door trustees meeting last week.

Trustees talked for hours with Dobelle and his lawyer in hope of reaching a settlement under which Dobelle would depart. At least some in attendance said afterward that the two sides appeared to be making progress.

"There was an effort to resolve it," said one person familiar with the negotiations. Trustees "talked about saying the hell with it and just give" Dobelle a deal that would allow him to walk away with no finding of wrongdoing.

Dobelle wanted an immediate sabbatical from his job as president, during which he would be paid at his presidential salary of $240,920 a year. He would eventually return as a tenured professor, probably at a salary of more than $100,000 a year.

Dobelle also wanted the university to pay his legal bills, already more than $100,000, from his fight with the trustees. He also wanted the trustees to stop their investigations.

In the end the trustees rejected Dobelle’s proposal because they thought it would be seen as rewarding bad behavior, say the people briefed on the meeting.

"You get a reward for doing a good job, not bankrupting a place," said Edward Marth, chairman of the board of the Westfield State College Foundation, the school’s fundraising arm.

Instead, after a long meeting with no break for lunch or dinner, the trustees placed Dobelle on paid leave while a law firm reviews the allegations against him.

The trustees asked for the keys to his Toyota Highlander, which the school had given him when he was hired in 2007. The trustees also took back his university cellphone and directed Dobelle not to contact university personnel.

"You don’t think it’s personal? How many times does the chairman of the board of a college ask a president to turn in his car keys?" said Dobelle’s publicist, George Regan.

It has been a steep fall for Dobelle, who at an August board meeting appeared to have the backing of most of the school’s 11 trustees.

But Dobelle’s actions in the past two months — including verbal attacks against Flynn, Freeland and Gov. Deval Patrick — helped galvanize the board, which voted unanimously to place Dobelle on leave.

Some trustees may also have been persuaded by the answers Dobelle gave to intense questioning by Betsy Scheibel, a trustee who formerly served as district attorney in Hampshire and Franklin counties, the official said.

She questioned Dobelle for more than an hour, and Dobelle’s answers only solidified the vote against him, the official said.

Dobelle’s suit, filed in U.S. District Court in Springfield, demands unspecified damages from Freeland and Flynn, as well as trustees Kevin Queenin and Scheibel and the accounting firm that did the original review of Dobelle’s spending, O’Connor & Drew of Braintree.

Aside from the lawsuit, Dobelle’s bargaining power appears to be limited. Under his employment agreement the trustees can terminate him — and pay him nothing — if they find he failed to follow "applicable policies or procedures governing the use and management of public moneys and trust funds."