Mr Bates was an RSPCA director until Friday, when he resigned. And he made his reasons public: he thought the organisation missed funding opportunities, spent too much on administration at the expense of animal welfare, mishandled bequests and more.

Four other directors had resigned from the board this year alone, though not all for the above reasons.

He had planned to continue volunteering his time at the shelter, where he had, until yesterday afternoon, put in two days' work a week.

"I was working on completing the chookhouse, a lovely chookhouse with a yard and everything," he said.

"The CEO called and identified himself.

"There was a little pregnant pause and then the following words came out: Your services as a volunteer at the Hobart shelter are no longer required. You are to leave immediately."

Mr Bates said he was given no reasons, only that a letter would follow in due course.

RSPCA chief executive Greg Tredinnick did not comment yesterday but society spokeswoman Lyndell Whyte said the action was "in response to a request from the staff and volunteers at the Hobart shelter".

No further details were provided.

Mr Bates said he was flabbergasted by the statement. He said he had a working relationship with everyone at the shelter.

"I am very upset by this. I came up here to help the animals," he said. "I've done so much here (at the shelter). So what if I've got an opinion that doesn't agree with theirs? I resigned from the board because of that - now I can't volunteer?

"Do I have no right to voice an opinion?"

He said he would go to the RSPCA annual meeting to be held in Launceston on Sunday. One motion to be debated calls for the resignation of president Scott Whitters.