A Bristol Employment Tribunal is this week hearing the case of a Christian school worker who was sacked after she shared a petition against compulsory sex education on her personal Facebook page.
Kristie Higgs is challenging her former employer, Farmor's School in Fairford, where she had worked for seven years prior to her dismissal in January last year.
Her dismissal came after she circulated a petition on Facebook in October 2018 encouraging friends and family to sign a petition challenging the compulsory Relationships and Sex Education curriculum that came into effect in English schools this month.
In a second post, Mrs Higgs shared an article from Judybeth.com on the rise of transgender ideology in children's books in American schools.
Adding her own comment to the post, she said: "This is happening in our primary schools now."
Following her personal Facebook posts, the school received an anonymous complaint describing them as "homophobic and prejudiced to the LGBT community".
After an internal investigation, she was sacked for gross misconduct without notice in January 2019.
She has turned to the Employment Tribunal after her appeal against her sacking was rejected.
Speaking ahead of the hearing, Mrs Higgs said Christians should be able to express their beliefs without fear of losing their jobs.
"Nothing could have prepared me for what happened. I was told that the reasons behind my sacking were nothing to do with my Christian beliefs – it had everything to do with my Christian beliefs," she said.
"The whole experience broke my heart.
"I have been punished for sharing concerns about Relationships and Sex Education. I hold these views because of my Christian beliefs, beliefs and views which are shared by hundreds of thousands of parents across the UK.
"My number one concern has always been the effect that learning about sex and gender in school will have on children at such a young age. I have not discriminated against anyone.
"Through my case I want there to be renewed freedom for others, especially Christians, to express their beliefs and opinions without fear of losing their jobs."
Andrea Williams, chief executive of the Christian Legal Centre, which is assisting Mrs Higgs, said she was a "kind, loving and courageous woman" who faces the prospect of never working with children again.
"This case is about the freedom to hold Christian views about what it means to be human. Many Christians have faced pressure for expressing these views in the workplace before, but in this case, Kristie has been dismissed for sharing her views among friends on Facebook," she said.
"What Kristie shared on Facebook simply reflects the genuine and justified concerns of a parent about the sexual ideology currently being imposed on her own children and thousands of children across the UK.
"Kristie has not only lost her job, but her whole career is now tarnished with the accusation that for holding these views she is now a danger to vulnerable children.
"This is despite an exemplary record at the school and in her work with youth in the wider community. If Kristie does not win this case, due to one complaint, she will never be able to work with children again."