A Brighton councillor has been expelled from the Green Party for her opposition of same-sex marriage, based on her Christian convictions.
Christina Summers said she was "crestfallen" by decision, having previous told the Party's disciplinary hearing "I'm accountable to God above any political party".
Brighton has the country's only Green MP, Caroline Lucas.
Several Green Councillors called for her dismissal when she voted against a motion in support of the Government’s plans to introduce same-sex marriage at a council meeting in July.
During the debate, where she was the only member to oppose the motion, Ms Summers said: "When you touch marriage, you're touching family and you're hitting at the very heart of God and I have an enormous problem with that."
After the debate, deputy council leader Phelim MacCafferty, the party spokesman on LGBT issues, said: “Councillor Summers has a long standing position of conscience about religious marriage based on her faith.
“Greens believe she is entitled to hold her view but this does not reflect the position, spirit and track record of the Green Party in extending human and civil rights for all social groups irrespective of sexual orientation or on other grounds."
On Monday, an inquiry panel decided to bar Summers from the party for violating its policy on gay marriage. Party members still have to vote to accept the inquiry's findings.
Summers said after the decision:“I have been waiting for weeks for my colleagues to make a clear and public decision.
“They have no idea how much I have been wanting to say to them and how many emails, blogs and tweets from the wider party membership I wanted to refute and respond to.
"But there is a time to speak and a time to be silent.
“In view of the Green Party's own special interpretation of equality, my expulsion from the Green Group of councillors should not, in the end, come as a surprise.
“Nonetheless, I can't help but feel crestfallen. After at least two intimate years of campaigning and then serving together in administration, my own colleagues, who should know me well by now, have chosen to believe a lie.
“Party policy, however vague, is sovereign”.
She added: "It's discriminatory against Christians. It's a typical symptom of prejudice, blatant prejudice.
"It raises a big question - can Christians serve in the public realm? They are saying don't bring your faith into politics."
The decision has divided opinion on social networking sites
Green MP Lucas told Pink News: “I was surprised that she chose to vote against it, I knew that she came from a particular Christian background, where for her that was going to be challenging.
"I was hoping very much that she wouldn’t vote against it, I was hoping at the very least she would abstain, and I regret very much that she did vote against.
“I absolutely understand how disappointed and angry people felt."
Summers said she would take advice from the Christian Legal Centre over whether to seek a judicial review of the party's decision.
Its chief executive Andrea Minichiello Williams said: “The decision to expel Christina Summers and the shambolic nature of the disciplinary proceedings against her reflect very badly on the Green Party.
“Brighton and Hove was the first council the Greens won. They cannot expect to win any more if they continue to suppress diversity and freedom of expression in this way.
“Councillor Summers’ view of marriage as being the union of a man and a woman is consistent with the teachings of mainstream, historic Christianity. Is the door of the Green Party now closed to Christians?
“The Party has wilted under pressure from its extremist elements and failed to uphold freedom and diversity of opinion at Councillor Summers’ expense”.
A spokesperson for the Green Party said they could not forcibly bar Summers from the party or remove her as an elected councillor.
"But in relation not to her speech or vote in the council chamber or her sincerely held religious views but in relation to her breach of her own written undertakings as a council candidate and her recent behaviour towards the party, she should be expelled."
The party said Summers had signed an agreement that she would uphold "equality for all people, regardless of race, colour, gender, sexual orientation, religion, social origin or any other prejudice".