The ECJ ruling is that the UK can decide to cancel A50, within the two years, and the EU cannot stop it doing so.
The issue is therefore at our end, not the EU's.
To cancel A50 we would need some legislation to reverse the original triggering of A50. Legislation can only be introduced by the Government (not parliament) and it takes time. By the end of Jan, we may not have the time (i am not an expert in legislation, but one issue is that it must "lay" in parliament for at least 21 days (might be wrong) before taking effect)
The ECJ ruling is that the UK can decide to cancel A50, within the two years, and the EU cannot stop it doing so.
The issue is therefore at our end, not the EU's.
To cancel A50 we would need some legislation to reverse the original triggering of A50. Legislation can only be introduced by the Government (not parliament) and it takes time. By the end of Jan, we may not have the time (i am not an expert in legislation, but one issue is that it must "lay" in parliament for at least 21 days (might be wrong) before taking effect)