Four British Christians who claim they lost their jobs as a result of discrimination against their beliefs are taking their cases to the European Court of Human Rights.
They include an airline worker stopped from wearing a cross and a registrar who did not want to marry gay couples.
All four lost separate employment tribunals relating to their beliefs.Their cases are being heard together at the court in Strasbourg.
The claimants are:
Nadia Eweida, a Pentecostal Christian from Twickenham, south-west London, who was sent home by her employer British Airways in 2006 after refusing to remove a necklace with a cross
Nurse Shirley Chaplin, of Devon, who was moved to a desk job by Royal Devon and Exeter NHS Trust Hospital for similar reasons
Gary McFarlane, a Bristol relationship counsellor, who was sacked by Relate after saying on a training course he might have had a conscientious objection to giving sex therapy advice to gay couples
Registrar Lilian Ladele, who was disciplined after she refused to conduct same-sex civil partnership ceremonies in north London
The National Secular Society said a court ruling in their favour would undermine equality law in Britain.