Royal Mail workers are to stage six more strikes next month, including on Christmas Eve, in a long-running dispute over pay, jobs and conditions.
The Communication Workers Union (CWU) said its members would walk out on 9, 11, 14, 15, 23 and 24 of December.
It is in addition to strikes already notified for November 24, 25 and 30, and 1 December.
The CWU said it still wanted a negotiated settlement but that bosses “need to wake up and realise we won’t allow them to destroy the livelihoods of postal workers”.
A Royal Mail spokesperson said: “Our preference is for an agreement with the CWU but the change we need is not optional.
“They should be focused on a resolution to this dispute for their members and the long-term health of the business, rather than damaging strike action.”
The announcement adds to months of strike action across various industries such as rail, universities and aviation.
Ground handlers at Heathrow Airport today announced a 72-hour strike over pay. About 350 workers will begin the action from 4am on Friday, the Unite union has said.