The High Court has upheld a classroom ban on a Christian school teacher who condemned the "homosexual lifestyle" in front of pupils.
In what is believed to be the first case of its kind, a judge rejected an appeal by science teacher Robert Haye against the decision to ban him indefinitely - a decision he says is likely to end his teaching career.
Mr Haye told a Year 11 class of students aged 15-16 that the way homosexual people lived was "disgusting" and a sin, according to the Bible.
He also told Year 9 pupils aged 13-14 on another occasion that "anyone who worships on Sunday is basically worshipping the devil".
Mr Haye, 43, and his family belong to the Seventh-day Adventist Church, which observes Saturday as the Sabbath.
Following his February 2010 comments at Deptford Green School in Lewisham, south-east London, a teaching assistant complained and triggered an investigation.
Mr Haye was sacked from his job at the 1,200-pupil inner city comprehensive.
He was also prohibited from teaching at any school or sixth form college last July after the Education Secretary backed a decision of regulatory body The Teaching Agency recommending the ban.
Mr Justice King rejected his appeal at London's High Court, saying the ban was justified because Mr Haye had shown lack of insight when he made his "inappropriate" comments and was found guilty of unacceptable professional conduct.
Mr Haye can apply to return to the classroom after two years. But he said after his High Court defeat he thought his teaching career in the UK was over because he was not prepared to give up his religious beliefs - and the right to express them - in order to teach again.
Now unemployed and facing a £4,200 legal costs bill, he said: "I will not recant my beliefs. God comes first."
He added: "Christians are now being persecuted in this country for believing in the Bible.
"That cannot be. We have a right to believe and express what we believe, but people are now afraid of being punished for not being politically correct.
"This country is a free and democratic society, but is it? Is it really?"
Robert Ogilvy, representing Mr Haye in court, said that no students had been distressed or offended by his comments and he had been responding to their questions, rather than propagating his Bible beliefs.
As well as science, Mr Haye taught personal, social, health and economic education (PSHE) and had a reputation as a good teacher.
Mr Ogilvy argued the teaching ban was "fundamentally unreasonable, unfair and disproportionate".
It violated Mr Haye's right to freedom of speech and freedom of religious belief under the European Convention on Human Rights.
Mr Ogilvy said the prohibition order would in reality amount to a life ban from teaching because Mr Haye was not prepared to "denounce or renounce" Bible teachings.
Dismissing the appeal, Mr Justice King said it was "misconceived and must fail".
The judge said: "This case is not about the right of a teacher to hold sincerely-held beliefs based on the Bible in relation to homosexuality or attendance at church on Sundays.
"It has been about how those beliefs and views are manifested in the context of teaching in schools with young people with diverse sexuality, backgrounds and beliefs."
The judge said Deptford Green had a policy which made it clear that teachers were expected to present positive information on lesbians, gays and bisexuals "to enable students to challenge derogatory stereotypes and prejudice".
The policy was part of "modern British values of tolerance", said the judge.
The human rights convention allowed limitations to be placed on free speech and religious belief in order to protect the rights of others, and in this case the limitations were "undoubtedly proportionate".