The postal strike in Oxford is set to continue after another meeting aimed at ending the dispute broke down. More than four million items of post have not been delivered because of the walkout by 400 workers at the centre in Cowley and two delivery offices.
The unofficial strike began on Tuesday 30 March over claims of bullying.
The workers met officials of the Communication Workers Union but said the strike would go on until a manager they accuse of bullying is removed.
The Royal Mail said it always took claims of bullying or harassment seriously and announced it had set up special "listening posts" for staff to voice concerns.