New Delhi: Tamil Nadu Chief Minister M.K. Stalin has written to eight non-BJP Chief Ministers, urging them to “oppose the reference sought by the President before the Supreme Court” over the powers and deadlines concerning gubernatorial assent to state legislation.Stalin has said that the move could “unsettle a landmark judgment” on federal powers and appealed to the other chief ministers in opposition-ruled states to “preserve and protect the basic structure of the Constitution,” reported The Indian Express.“I am now writing to you to personally request your good selves to oppose this reference… We must evolve a coordinated legal strategy before the court and present a united front to preserve and protect the basic structure of the Constitution,” Stalin has said in the letter.Earlier, President Droupadi Murmu had sent a 14-point Presidential Reference to the Supreme Court for its opinion on some of its own powers.The Reference concerns the apex court’s landmark judgment in State of Tamil Nadu vs Governor of Tamil Nadu, in which the Supreme Court set timelines for the president to act as per Article 201 of the constitution on the Bills which a governor has reserved for her assent. The Supreme Court had said that Tamil Nadu governor R.N. Ravi’s move to reserve 10 Bills for the president’s assent was illegal.In the Presidential Reference, which reports say was sent on May 13, Murmu asks whether the court can use its powers under Article 143 to “impose” timelines and prescribe how the president and governors should act while considering Bills sent to them for assent.‘BJP-led Union government has used Governors to obstruct functioning of Opposition-ruled States’“We have all been witness to the way in which the BJP-led Union government has used Governors to obstruct and impede the functioning of Opposition-ruled States,” Stalin has said in his letter to the chief ministers.The recipients of the letter are believed to include the chief ministers of West Bengal, Kerala, Telangana, Punjab, Bihar, Jharkhand and Andhra Pradesh.“They have been able to do so by taking advantage of the fact that the Constitution is silent on certain issues, because the framers of the Constitution trusted that those holding high constitutional office would act in accordance with constitutional morality,” Stalin has written in his letter.