Travellers in the north west are being urged to plan their journeys and check before they travel, ahead of industrial action on both the Merseyrail network and Northern services on Monday.
While train users will be most directly impacted, officials say the whole transport network is expected to be busier as people find other ways to travel.
Merseyrail services are planned to run every half hour on all routes from around 7am to 7pm. All trains will be six carriages long.
However, passengers are strongly advised to check the Merseyrail website and Twitter feed before travelling as it is possible that timetables will change prior to, as well as during, strike action.
Meanwhile, passengers who travel with Northern are also advised to check before they travel as the operator will also be running a greatly reduced, and revised, timetable. Services by other mainline train operators will continue to run as normal.