Principle of adherence of jurisdiction

What is this principle of adherence of jurisdiction or continuing jurisdiction? This principle states that once a court acquires jurisdiction over a controversy, it shall continue to exercise such jurisdiction until the final determination of the case.

The general rule is that the court shall retain jurisdiction over the controversy regardless of subsequent amendments and improvements.

What is the exception to the above-mentioned general rule? The exception is that where the succeeding statute expressly provides, or is construed that it is intended to operate to actions pending before its enactment.