Samajwadi Party veteran Mulyam Singh Yadav on Wednesday shocked the Opposition parties when he congratulated Prime Minister Narendra Modi and said he hoped that he will become the prime minister again.

Mulayam made these remarks in the Lok Sabha with UPA chairperson Sonia Gandhi by his side. Sonia appeared amused by the former Uttar Pradesh chief minister's comment, which was made during the valedictory references by political leaders before the 16th Lok Sabha adjourned sine die.

"The prime minister has made all efforts to take everyone along. It is my wish that all those who are members here return victorious to this House. And Mr Prime Minister, you should become prime minister again," the 79-year-old Mulayam said.

While Sonia was seen smiling at the veteran leader's remarks, most members broke into a hearty laugh, and Modi acknowledged the remarks with folded hands and bowed head.

When Modi took the floor to make his observations, he said a lot of work is yet to be done. "There is so much to do... and Mulayam Singhji has already given his blessings. I am very grateful to him," the prime minister said.

Congress president Rahul Gandhi, who was addressing a press conference on the Rafale deal, chose to downplay Mulayam's remarks.

"I disagree with him. But Mulayam Singh Yadav has had a role in politics and I respect his role," Rahul said.

NCP leader in the Lok Sabha Supriya Sule also made light of the remarks saying the SP veteran had made similar remarks in 2014 when prime minister Manmohan Singh was in office.

Interestingly, Mulyam's remarks came on a day when the Opposition had gathered in the capital at a show of unity ahead of the Lok Sabha elections.

West Bengal Chief Minister Mamata Banerjee, Andhra Pradesh Chief Minister N Chandrababu Naidu, NCP leader Sharad Pawar, Congress leader Anand Sharma, CPM general secretary Sitaram Yechury and former J&K chief minister Farooq Abdullah spoke at a rally organised by Delhi Chief Minister and AAP convenor Arvind Kejriwal.