Rail bosses have managed to increase the number of trains operating on a 17th consecutive Saturday of strikes.
Eight Northern trains will run in either direction on the Newcastle-Middlesbrough line between Sunderland, Hartlepool, Seaham, Seaton Carew and Billingham stations on December 15.
Some previous Saturdays during the dispute have seen as few as five services operating as part of emergency timetables.
The latest action also brings the number of strike days to 40 since the dispute started last year.
The disagreement between Northern's parent company, Arriva Rail North (ARN), and the Rail Maritime and Transport (RMT) union centres on guarantees over the future role of guards.
The RMT fears staff and passengers will be at greater risk if trains driver-only services are introduced as part of a new fleet of trains.
Arriva, however, insists guards will continue to have jobs until the end of Northern's current franchise in 2025.
David Brown, managing director at Northern, said: “By the end of December, we will have had 19 consecutive Saturdays of RMT strike action. This targeted action disrupts our customers’ lives.
"But, as we enter a vital period for businesses, it also damages the economic well being of the north of England.
“We have fantastic colleagues who have supported customers by keeping our trains running on each of the RMT strike days.
"We are aiming to keep as many people moving as possible and ensuring customers can still travel into the biggest towns and cities for the big seasonal events including Christmas markets but with very few services running after 5pm."
Full details of Saturday's services are available at https://www.northernrailway.co.uk/strike or by ringing 0800 200 6060.