"A person who can't be loyal to his father, can't be loyal to anyone," he reportedly said at a public event in Mainpuri on Saturday.
Ahead of the state assembly elections in Uttar Pradesh, Akhilesh had snatched reins of the party from Mulayam and their fight also reached the Election Commission.
Mulayam, who has since been given the role of party mentor, had openly criticized the Samajwadi-Congress alliance and was virtually absent from the campaign too.
During the campaign, Mulayam addressed just two rallies, one for Shivpal and the other for Sadhana's daughter-in-law Aparna Yadav.
However, at the swearing-in ceremony of Yogi Adityanath on March 19, Maulayam had reportedly whispered, "Thoda Akhilesh ka khayal rakhiye (Please take care of Akhilesh)" into PM Narendra Modi’s ears.