An extraordinary general meeting of the Dublin Simon Community to discus a motion of no confidence in the board will be held next month.
It has also emerged that the dismissed former chief executive of the charity, Mr Greg Maxwell, has lodged a case with the Employment Appeals Tribunal (EAT) seeking his reinstatement.
No date has been set for the hearing.
Sources within the Dublin Simon Community say there has been huge unease since Mr Maxwell was dismissed in August having held the post for nine years.
"Greg was never accused of any misbehaviour. Not only had he done nothing wrong, he had performed well.
"The dismissal has been hanging over the organisation, and people need clarity," said one senior source.
The motion being tabled at next month's meeting is: "In view of the process that led to the dismissal of Greg Maxwell as CEO of Dublin Simon and our concerns about developments since then and concerns for the future of the community, this meeting has no confidence in the board of Dublin Simon."
Since Mr Maxwell's dismissal it is understood several senior staff and voluntary members have left, including the public relations manager, Mr Bob Jordan, and Mr Ray Watson, a former chairman of the charity.
One of those instrumental in tabling the motion at next month's e.g.m. said yesterday supporters of Mr Maxwell had gathered 49 signatures - 10 per cent of the membership.
"We could have gone on and gathered many, many more. The board accepted the call for an e.g.m., and that now has to be held by the end of January."
They have also asked that the board not appoint a new CEO until after the e.g.m. The board has advertised the post, which is currently held on an interim basis by Mr Sam McGuinness, a former manager in the private sector.
Mr Tony Bateman, a member of the current board since April, told The Irish Times last week the board welcomed the e.g.m. as "an opportunity for everyone to express their opinions and to have a say in the running of Dublin Simon".
"It's an opportunity that hasn't been there to clear the air. This has been a very troubled time for the board and the other people in Simon."
He stressed that Dublin Simon's work with the homeless had been unaffected by events since August.
"In dismissing Gregg we took a decision to do what was best for Dublin Simon."
Asked what he meant, he referred to the pending case at the EAT, saying: "We are in a situation where there are other procedures taking place, and it would be unfair to say anything about that."
Asked whether the board would resign if the motion of no confidence was passed, Mr Bateman said it would be up to the community to ask for its resignation.
