The Billy Graham Evangelistic Association (BGEA) and a congregation in the Free Church of Scotland are taking legal action after a conference centre cancelled their booking apparently over their views on marriage and sexuality.
The case against the Robertson Trust will be heard at Glasgow Sheriff's Court over the course of three days next week.
The BGEA and Stirling Free Church are claiming breach of contract and religious bias after their booking for meetings at the trust-owned Barracks Conference Centre were cancelled in November 2019.
The Christian Institute, which is defending the BGEA and the church, says that contracts signed when booking for church services and a BGEA conference permitted the use of the premises "for public worship and delivery of religious instruction".
When both contracts were abruptly cancelled a few days later, it says trust claimed to have a policy preventing it from renting space for activities promoting religion or politics.
When the church wrote to the trust's head of finance asking for a copy of the policy, they were informed that there was no explicit policy but that decisions were made "on a case by case basis with the funding policy regarding 'projects and activities which incorporate the promotion of political or religious beliefs' being an example of what we would take into consideration".
When the BGEA and church announced they would be taking legal action, the trust changed its trust deed, purporting to ban renting to religious and political groups.
The court will hear claims that the trust's CEO was hostile to the belief that marriage is between a man and a woman, and that she was angered by the leasing of the premises to the church and BGEA.
Speaking in advance of next week's hearing, Stirling Free Church minister Rev Iain MacAskill said: "We are a thriving church that welcomes all people and preaches the gospel of Jesus Christ.
"We were shocked to be told we could no longer use the Barracks for our Sunday services. We had negotiated with the trust in good faith and their contract expressly refers to us using the premises for religious worship.
"The Free Church believes marriage is between a man and a woman – a mainstream Christian belief shared with the Church of Scotland and the Church of England.
"We had no problems with trust staff during our negotiations. The staff seemed embarrassed when they had to tell us they were terminating our arrangement. We have had no other option but to resort to legal action."
The hearing next week follows the BGEA's recent successful discrimination claim against Blackpool Council after it pulled bus adverts for the Lancashire Festival of Hope featuring BGEA CEO Franklin Graham.
In that case, the courts ruled that Blackpool Council's actions had breached the festival organisers' human rights, and were "the antithesis of the manner in which a public authority should behave in a democratic society".
The BGEA's Roger Chilvers said: "The Billy Graham Evangelistic Association booked a room at the Barracks for a training course for churches involved in our outreach programme, the Graham Tour UK. We made it clear to the venue at the time of booking that we are a Christian organisation. It was only later that they came back and said they were cancelling our booking because of our religion.
"If the Barracks was a religion or belief organisation, the law would allow it to be selective in not hiring out its premises to groups that don't share its beliefs. But the Barracks is not a religion or belief organisation. It is a neutral space, offered to the public at large.
"You can't have a situation where religious groups are banned from hiring neutral spaces. That is not a free society.
"This is anti-religious discrimination, plain and simple, and we are hopeful the court will uphold our claim and recognize the inequities present in this case."
Simon Calvert, the Christian Institute's Deputy Director for Public Affairs, said: "Scotland's biggest grant-making trust pride themselves on serving the community. But at the heart of the community are lots of religious groups which exist to express their faith. Do they not count?
"It's quite clear there is some hostility within the trust towards Christian beliefs about marriage. But these beliefs are protected by equality and human rights law. The courts have ruled again and again that you can't discriminate against people just for believing in traditional marriage."