Transport authority Merseytravel and franchisee Merseyrail will introduce a £1 flat return fare on Thursday evenings from this week.
The deal will be available on Northern and Wirral Merseyrail Lines for six weeks. As well as Thursday evenings it will run all day every Sunday during December. The annual Christmas offer is in its 15th year.
Bart Schmeink, managing director of Merseyrail, added: "We are keen to show the people of Merseyside and beyond that using the train to get to city and town centres is an excellent way to avoid traffic jams and parking problems. The Christmas Cracker promotion will hopefully encourage even more people to leave their cars behind and use Merseyrail to get to the shops."
This year the offer is valid on Merseyrail's Wirral and Northern Lines, but not the City Lines to Warrington, Earlestown or Wigan. The £1 return flat fare extends to stations as far as Southport, Ormskirk, Kirkby, West Kirby, New Brighton, Ellesmere Port, Chester and Liverpool city centre stations.
The offer means customers can travel from Southport to Chester and back for £1. A total of 31 Merseyrail stations currently offer free park and ride facilities.