In his resignation letter to Akhilesh, Maurya said, "I had got an opportunity to work under your leadership in harmony. But after our talks on February 12 and my resignation (as party general secretary) on February 13, no initiative was taken to talk to me.
"So I am resigning from the party's primary membership as well."
Maurya cited his ideological differences with Akhilesh as the reason behind his resignation.
He said Akhilesh was acting against the "socialist ideology".
Maurya, 70, joined the SP in 2022 after quitting Bharatiya Janata Party (BJP).
The former state minister under Chief Minister Yogi Adityanath joined the BJP years after serving Mayawati's Bahujan Samaj Party (BSP).