the offending portion of the G.O.Ms.No.74, dated 27.06.2013, namely, paragraph 6 which is extracted supra, is unconstitutional and it only seeks to introduce a naked discrimination in the matter of treatment of identically placed employees. As rightly contended y the learned counsels appearing for the petitioners and in view of the various decisions rendered by this Court, the right which is accrued to the employees cannot stand negated by giving retrospective effect to the G.O.Ms.No.74, dated 27.06.2013. Moreover, in the several decisions rendered by this Court which have been confirmed in Writ Appeals and also in some other cases by the Hon'ble Supreme Court, it does not lie within the power of Government to bring the impugned G.O. with retrospective effect. Such retrospectivity is blatant attempt by the Government to violate the principles of promissory and equitable estoppel and doctrine of legitimate expectation. 21. This Court also cannot lose sight of the fact that in several cases, in fact, few of them have cite above, the employees had obtained beneficial orders and those orders also came to be implemented by the Government on various dates even in the present year. In the said circumstances, this Court is unable to understand the situation as to how the petitioners alone can be singled out for discriminatory treatment by retrospectively applying the G.O.Ms.No.74, dated 27.06.2013. Any Government action is to be tested on the touchstone of Articles 14 and 16 of the Constitution of India. A State cannot be allowed to adopt the discriminatory practice while dealing with the citizens of Government servants. 22. In the instant case, the attempt to implement the impugned G.O.Ms.No.74, dated 27.06.2013, with retrospective effect, is nothing but a clear case of colourable exercise of power. The fundamental rights guaranteed by our Constitution sought to be impinged by bringing in the impugned G.O. with retrospective effect. Exercise of such power, therefore, cannot be held to be