Right of appeal U/s. 260A is a substantive right and cannot be impaired by any subsequent legislation

Right of appeal is not a matter of procedure and that it is a substantive right. It is also recognized that this right gets vested in the litigants at the commencement of the lis and, therefore, such a vested right cannot be taken away or cannot be impaired or imperilled or made more stringent or onerous by any subsequent legislation unless the subsequent legislation said so either expressly or by necessary intendment. An intention to interfere with or impair or imperil a vested right cannot be presumed unless such intention be clearly manifested by express words or by necessary implication. ...