The Vermont State Employees Association board fired its executive director Wednesday, in a move that caught some members off-guard.

The board of trustees voted 10-5 to oust Mark Mitchell after an executive session that spanned the better part of the day.

Board President John Reese, who supports Mitchell, said he was “blindsided” by the action, and Sheila Coniff, a board member who also backs Mitchell, said it “came completely out of the blue.”

The VSEA represents more than 5,000 state employees, making it the state’s second largest union. Mitchell assumed his spot at the helm in December 2011.

Doug Gibson, the union’s spokesperson, said he could not comment on personnel issues, but he confirmed that Mitchell no longer had a job at the union as of close-of-business Wednesday.

A story by Paul Heintz of Seven Days in October cited frustration with Mitchell among several recently departed VSEA staff members, state officials and legislators.

Though taken aback by the board’s vote, Reese said he had been aware of discontent among the VSEA ranks. He described it as “a small faction of individuals that have been fighting tooth and nail against everything Mark and I have been doing for the organization.”

According to Reese — who said he couldn’t offer further detail — the board was presented with multiple allegations made against Mitchell by VSEA staff.

“Staff members approached the board with a series of allegations, some of them substantive, if proven true, but none of them criminal,” Reese said. “Mark hasn’t done anything egregious or malicious. A lot of the allegations were personal things. It was clear it was more of a personal attack rather than, ‘oh, gee, we’ve got to save our organization from doom.’”

Three board members said they couldn’t speak about the allegations because they were revealed during an executive session; the remainder could not be reached for comment.

Former VSEA President Bob Hooper, who currently serves on the executive committee of the retirees chapter, said concerns with Mitchell have been percolating for a while. “It’s something you had to see coming,” Hooper said, citing strained relations between Mitchell and members of the Shumlin administration and the Legislature.

The board reconvenes Monday, and Reese said he is hoping it will reconsider its decision. In order for that to happen, one of the board members who voted to fire Mitchell would have to make a motion to reinstate him.

Reese, as president, doesn’t have a vote, and he was out of town for Wednesday’s meeting, which meant another board member, Shelley Martin, chaired the meeting and therefore she couldn’t vote either. Martin couldn’t be reached before this story was posted, but according to Reese, she supports Mitchell.

Reese said he thinks the board “owes it to Mitchell” to at least order an independent investigation of the claims.

The board plans to vote Monday on who will take over Mitchell’s duties while they search for a replacement; Reese says it’s likely that responsibility will fall to Mike Casey, general counsel for VSEA.

The decision, Reese said, was made at a particularly inconvenient time.

“It comes at a very bad time for the organization,” he said. “We’ve been doing a lot of rebuilding … we are heading into our own elections and on top of that, we are about to go into bargaining. It’s really important to have a strong and competent leader at this time, and that’s what Mark has been.”