British Airways employee Nadia Eweida had argued the airline's denial of her wearing a cross contravened articles nine and 14 of the European Convention on Human Rights, which prohibit religious discrimination and allow "freedom of thought, conscience and religion".
Lawyers for the Government, which contested the claim, argued her rights were only protected in private.
But judges today ruled there had been a violation of article nine (freedom of religion), by five votes to two.
After being sent home in September 2006 for displaying the silver cross around her neck, Ms Eweida returned to work in customer services at Heathrow Airport's Terminal 5 in February 2007 after BA changed its uniform policy on visible items of jewellery.
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