A Labour councillor at the forefront of the Save Stobhill Hospital campaign is to appear before the party's National Constitutional Committee (NCC).
A spokesman for the Scottish Labour Party confirmed that Milton of Campsie councillor Charles Kennedy has been accused by the local branch of breaking party rules.
Chairman of the Strathkelvin and Bearsden Constituency Labour Party Peter Ritchie declined to comment, but the Herald believes Councillor Kennedy has been accused of supporting Save Stobhill candidate Dr Jean Turner in last year's Scottish Parliament elections rather than Labour candidate Brian Fitzpatrick.
A Scottish Labour Party spokesman said: "The local party believes Charles Kennedy may have broken party rules. The matter is with the NCC, who will hear the case at a future date."
But Councillor Kennedy, a leading member of the Save Stobhill Campaign group, warned party officials this week that he would not be gagged over the hospital's future.
He said: "This is a vendetta designed to stop me speaking out for Stobhill.
"I will defend my position vigorously, but I will not be silenced. Fighting to save Stobhill General Hospital goes way beyond party politics."
He added: "I would call on the people who have made these allegations to come out and show their faces."
One of the first to jump to Councillor Kennedy's defence this week was Tory Billy Hendry.
He said: "I'm not trying to score political points, Stobhill is too important an issue for that, but I am shocked and disappointed by the way the local Labour party is treating Councillor Kennedy.
"Labour MSP Brian Fitzpatrick did not stand up for Stobhill, but Charles Kennedy has.
"The only crime he has committed has been to speak out for the people of East Dunbartonshire on the most important issue that has faced our community in decades."
Chairman of Milton of Campsie Labour Party John Telfer said: "This is absolute nonsense. I was Charles Kennedy's election agent and not once did he encourage people to vote for Jean Turner.
"The Milton of Campsie Labour Party is 100 per cent behind him. He is an excellent councillor and is not afraid to speak up for his community. We need more like him."
Former Labour provost of Strathkelvin, Bobby Coyle, said it was a sad day for the local Labour party.
He added: "Long before this crowd came in, Charles Kennedy was fighting for Stobhill. The claims they are making against him are ridiculous.
"I don't know what the Labour Party is coming too, rounding on one of their best councillors. Those responsible are glory hunters, they are certainly not socialists."
And former Strathkelvin councillor, and lifelong Labour Party member, Bridget Dunion said: "Charles Kennedy is doing exactly what he was elected to do - speaking out for the ordinary people. They are the people who use Stobhill, and I admire him for doing that.
"He has listened to the voice of the community and is representing the people who live in that community.
"Charles Kennedy is a marvellous councillor. When I was a councillor we may have disagreed on some issues, but he was always prepared to listen."