Two Christians from London will be part of a landmark case on religious freedom at the European Court of Human Rights later.
Nadia Eweida and Lillian Ladele have joined forces with two other workers, arguing that their employers contravened the European Convention on Human Rights, which prohibits religious discrimination and safeguards the right to "freedom of thought, conscience and religion".
British Airways worker Nadia Eweida, from Twickenham received widespread publicity when she was sent home in 2006 after refusing to remove a necklace with a cross, or hide it from view.
An employment tribunal ruled Ms Eweida, whom court documents say is a Coptic Christian originally from Egypt, had not suffered religious discrimination, but the airline changed its uniform policy after the case to allow all religious symbols, including crosses.
Registrar Lillian Ladele was disciplined after she refused to conduct same-sex civil partnership ceremonies in Islington.