The Scottish Government has given assurances that it will be illegal for anyone to be discriminated against because they hold to the traditional definition of marriage as a union between one man and one woman.

The assurances were given in a meeting last week at the Scottish Parliament between Alex Neil, the minister overseeing the same-sex marriage bill, and the Reverend David Robertson, a Free Church minister in Dundee.

Mr Robertson, a director of the Solas Centre for Public Christianity, was concerned that Christians could be persecuted because of their views after same-sex marriage has been legalised.

He also feared churches would have their charity status revoked by OSCR, Scotland's charity watchdog, for breaking new equality laws.

Mr Robertson said it felt like Christianity was the religion that "dare not speak its name in Scotland" and that many Christians are deeply concerned that pro-marriage equality groups want to banish Christians and other people with a traditional understanding of marriage from the public square.

"Mr Neil categorically said it would be unlawful for any individual or organisation to be discriminated against because they believe marriage is between a man and a woman," he said after the meeting.

"Supporters of the gay lobby have accused people like me of hate crimes and being bigoted for continuing to insist that marriage is between a man and a woman, and I am grateful that the Scottish Government agrees these kind of claims for litigation have no place in 21st century Scotland."

The Free Church is strongly opposed to the redefinition of marriage. During the meeting, Mr Neil conceded that if he were to poll the general public on Princes Street, the main shopping street in Edinburgh, gay marriage would not feature in people's top ten list of concerns for modern Scotland.

Mr Robertson suggested a referendum should be held on the issue.

He concluded: "I am grateful for Mr Neil's frank honesty, and the Scottish Government's own consultation showed that many Scots are opposed to this proposal.

"We are continually told that the majority of Scots are for this - if this were the case why are the politicians so scared to let the people have their say in a referendum on this subject?

"Meanwhile the Government has paid the Equality Network to produce a video which shows leading politicians and celebrities saying 'yes' to what they term equal marriage.

"I would challenge any one of these politicians and celebrities to tell us what their new version of marriage actually is and why they consider it to be equal."