Heathrow check-in worker Nadia Eweida was sent home after refusing to remove the crucifix which breached BA's dress code.
Her treatment by BA - which styles itself as the "world's favourite airline" - brought condemnation both from Christian groups and members of other faiths last night.
BA's chief executive Willie Walsh has upheld the action against Miss Eweida for failing to comply with "uniform regulations" despite himself coming under fire recently for failing to wear a tie.
Miss Eweida, who has an unblemished record during seven years at BA, is suing her employer for religious discrimination after being suspended from work without pay for two weeks.
She said her treatment was all the more extraordinary as she and fellow employees had just undergone "diversity training" - including receiving advice from pressure group Stonewall on how to treat gays and lesbians in the workplace.
The airline's uniform code states that staff must not wear visible jewellery or other 'adornments' while on duty without permission from management.
It makes exceptions for Muslim and Sikh minorities by allowing them to wear hijabs and turbans.
Under rules drawn up by BA's 'diversity team' and 'uniform committee', Sikh employees can even wear the traditional iron bangle - even though this would usually be classed as jewellery - while Muslim workers are also allowed prayer breaks during work time.
But Miss Eweida, 55, from Twickenham, insisted her cross, which is smaller than a ten pence piece, was not jewellery but an expression of her deep Christian faith.
She questioned why she was being forced to hide her religion when BA's Muslim and Sikh workers could express theirs.
Miss Eweida said last night: "I will not hide my belief in the Lord Jesus. British Airways permits Muslims to wear a headscarf, Sikhs to wear a turban and other faiths religious apparel.
News RSS