Ndume was suspended last week by the Senate for triggering investigations into allegations of forgery against Bukola Saraki and his friend, Dino Melaye.
Reports accused Saraki of importing a Range Rover SUV without paying appropriate import duty, and attempting to clear the vehicle with falsified papers.
Dino, on his part, was accused of falsely claiming he graduated from Ahmadu Bello University.
The Senate dismissed both allegations, and sanctioned Ndume by suspending him for six months.
There have been moves by Borno politicians to get Ndume reinstated.
The protesters arrived the National Assembly gate early Tuesday, with placards lambasting Saraki and the Senate.
One placard read; “Saraki is a curse”.