From Begum v Denbigh High School [2006] UKHL 15 (apologies, as they say, for length)

The Strasbourg institutions have not been at all ready to find an interference with the right to manifest religious belief in practice or observance where a person has voluntarily accepted an employment or role which does not accommodate that practice or observance and there are other means open to the person to practise or observe his or her religion without undue hardship or inconvenience. Thus in X v Denmark (1976) 5 DR 157 a clergyman was held to have accepted the discipline of his church when he took employment, and his right to leave the church guaranteed his freedom of religion. His claim under article 9 failed. In Kjeldsen, Busk Madsen and Pedersen v Denmark (1976) 1 EHRR 711, paras 54 and 57, parents’ philosophical and religious objections to sex education in state schools was rejected on the ground that they could send their children to state schools or educate them at home. The applicant’s article 9 claim in Ahmad, above, paras 13, 14 and 15, failed because he had accepted a contract which did not provide for him to absent himself from his teaching duties to attend prayers, he had not brought his religious requirements to the employer’s notice when seeking employment and he was at all times free to seek other employment which would accommodate his religious observance. … In rejecting the applicant’s claim in Konttinen v Finland (1996) 87-A DR 68 the Commission pointed out, in para 1, page 75, that he had not been pressured to change his religious views or prevented from manifesting his religion or belief; having found that his working hours conflicted with his religious convictions, he was free to relinquish his post. … In Stedman v United Kingdom (1997) 23 EHRR CD 168 it was fatal to the applicant’s article 9 claim that she was free to resign rather than work on Sundays. The applicant in Kalaç, above, paras 28-29, failed because he had, in choosing a military career, accepted of his own accord a system of military discipline that by its nature implied the possibility of special limitations on certain rights and freedoms, and he had been able to fulfil the ordinary obligations of Muslim belief…

The ‘margin of appreciation’ given to employers to rigidly set their behavioural code would seem to be wide. But simple expression of a view, outside of a work context, may fall outside it. There are some surprisingly generous decisions to restricting freedom of speech in civil servants however, eg you can’t be in the Communist Party and so on. If anyone knows of an authority on the precise point then please let us all know.

The missing *not* was a typo, but a grievous one!

http://www.timesonline.co.uk/tol/comment/faith/article6093378.ece

You may also want to edit your second paragraph, as the original story quotes the employee as saying that he was *not* homophobic.