Senator Dino Melaye attacked Buhari during senate sitting on Thursday
When Buhari received members of his campaign organisation at the presidential villa last week, he criticised his predecessors and lawmakers.
Buhari had rhetorically asked what lawmakers have been doing in the national assembly, portraying them as a lazy bunch of overpaid and over-pampered legislators.
Melaye who has been away on trial, didn't like the president's tone and said so during plenary.
"As a senator of the federal republic of Nigeria who came to the national assembly in 2007, about 11 years ago, I am particularly unhappy that my privilege was abused by the president of the Federal Republic of Nigeria, President Muhammadu Buhari last week", Melaye said.
Addressing Senate President Bukola Saraki, Melaye continued: "Mr president, the president at the presidential villa while addressing a delegation of the campaign organisation; and this was televised on Channels TV and AIT and I have a copy to tender before the senate.....
"The President of the Federal Republic of Nigeria in his address said he does not know what we are doing. He said some of us have been in the national assembly for over 10 years and we have nothing to show for it and I say this statement is not only unpresidential but is an insult on my person and the institution of the national assembly where I'm proudly a member.
"Such derogatory statements and insult on the national assembly should not be allowed to go unnoticed. I'm very proud to be a member of the national assembly that I have been for the past 11 years.
"For the President of the Federal Republic of Nigeria to speak in such tone about the national assembly of Nigeria...I ask myself if Donald Trump will address Congress in like manner".
Melaye also said Buhari is the reason why heads of agencies and parastatals shun senate summons.
"One then begins to wonder why you will summon the IGP (Inspector General of Police) and he will refuse to come.
"We are not surprised that Director-Generals of parastatals or agencies will refuse to honour summons of the national assembly because the body language of the president is demeaning the national assembly.
"I feel I should bring this to the notice of this senate. The occasion where the president made this statement is an event of BSO (Buhari Support Organisation) led by Comptroller-General of Customs. CG of customs is a rank in a para-military organisation, if the CG customs will be leading a Buhari campiagn delegation, it is an aberration to his oath of office".
Melaye opted to sit with PDP senators when he resumed sitting on Wednesday May 30, 2018.
The senator said he was no longer comfortable sitting beside APC lawmakers.
Melaye was elected senator on the APC platform. However, his body language, posturing and utterances in recent times indicate he's considering a defection to the PDP from whence he came.