New Delhi: Indian National Congress Senior, a former Union minister Ghulam Nabi Azad has today quit the party submitting Resignation Letter to Sonia Gandhi mentioning Rahul Gandhi for his immature politics and for demolishing the consultative system in the Congress party. In an explosive letter to party principal Sonia Gandhi, the former Jammu and Kashmir Chief Minister said he is resigning to all his positions and the primary class of the Congress.