Train drivers will join Border Force staff in launching action, along with some ground handlers, as the post-new year rush and return to work begins.
Here are the key disputes and dates to be aware of.
Rail
Rail union Aslef has now joined the RMT in planned strikes over 3-4 January and 6-7 January, ensuring the return to work is affected.
A whole week of disruption is forecast, as there are unlikely to be many early trains on 5 January due to train and crew displacement.
