Which train station is best for parking and taking train to London?

[whosiwhatsit]

We'd like to park at a train station and then take the train directly to London with no changes. Which station would be best for this? I'm guessing stations in the centre of Liverpool will charge more for parking so is there a station in the surrounding area (say within half an hour or a bit more driving) where we could park reasonably inexpensively and then get to London fairly quickly by train? Thanks for any advice you can give us.

Hello. The only place the London train stops near Liverpool is Runcorn. I think you can park there but not sure how much cheaper than town it would be. Otherwise, if you can put up with one change, Liverpool south parkway has a big carpark.