Universal has said it wants to open its first European theme park and resort on land at Kempston Hardwick, south of Bedford, in 2031.
More than eight million visitors are expected to head to the attraction in its first year.
According to EWR, Universal initially plans to run shuttle buses from Milton Keynes to the theme park.
But the rail company said by “fast-tracking” an upgrade of the existing rail line between Bletchley and Bedford – known as the Marston Vale Line – EWR trains could “serve the park within its first few years”.
The nine current Marston Vale stations will be closed with four new replacement stations built at Woburn Sands, Ridgmont, Lidlington and Stewartby.
Stewartby station will serve Universal, with four trains an hour running between there and Oxford “by the early 2030s”, EWR said.