A judicial review decision on five separate appeals over the Government’s High Speed Rail project is expected to be made early in 2013.
Campaigners, including Cherwell District Council, took their fight over the £33bn project to the High Court.
Legal arguments for the five separate judicial reviews finished on Thursday, after nine days.
The London-Birmingham link would cut across north east Oxfordshire including Finmere and Mixbury on the Oxfordshire border.
Conservative-controlled Cherwell District Council is one of 18 local authorities from the 51M group challenging the plans.