A Manchester housing worker is taking legal action against his employer after being demoted for posting comments about gay marriage on Facebook.
Adrian Smith had his pay cut by 40% when he lost his managerial post at Trafford Housing Trust (THT) and was redeployed as an adviser.
Mr Smith, 54, who stated that he was a THT manager on his Facebook page, wrote that "marriage is for men and women".
The trust said he had been disciplined for breaching its code of conduct.
Mr Smith is being supported in his legal action by The Christian Institute, a national charity that defends the religious liberty of Christians.
He is claiming interference with his rights to free speech and religious liberty and breach of contract, the institute said.
Under the housing trust's code, staff are expected to ensure that their opinions cannot be mistaken as being the opinions of the trust.
The father-of two, from Bolton, wrote "an equality too far" on his page next to a BBC News Online story with the headline, "Gay church 'marriage' set to get the go-ahead".
A THT spokeswoman said: "At the end of 2010, we updated our Code of Conduct for Employees and provided it to all staff.
"This version of the code clearly set out what use employees can make of social networking sites such as Facebook.
"Some three months after this new code was issued, Mr Smith, without our authority or knowledge and on a Facebook page that identified him as a manager at Trafford Housing Trust, made comments that were found, by a full disciplinary investigation in which he had trade union representation, to be in breach of the company's code of conduct and other policies.
"Mr Smith was disciplined for his breach of company policy. The trust made no comment about any personal beliefs that he holds."
Mr Smith went on to comment on his Facebook page that, "The Bible is quite specific that marriage is for men and women".
"If the state wants to offer civil marriages to the same sex then that is up to the state; but the state shouldn't impose its rules on places of faith and conscience", he wrote.
His solicitor Tom Ellis, of Aughton Ainsworth law firm, said: "It is an extreme and massive overreaction by the trust that a man can lose his job over what I imagine most people would find are not extreme views.
"They weren't intended to be offensive and are an opinion over which he has suffered a huge pay cut."
The THT said it would vigorously defend itself through the county court.