Nairobi Senator Sakaja Johnson and 21 matatu saccos have taken on City Hall and Governor Mike over their decision to ban public service vehicles from the Central Business District (CBD).
In his case filed at the High Court on Monday morning, Mr Sakaja accuses Mr Sonko of failing to consult the public and stakeholders before effecting the ban.
City Hall, he argues, has also not provided millions of commuters viable alternatives to make their commute smooth and comfortable.
Police and traffic marshals started effecting the ban early Monday morning, forcing matatus to drop off passengers outside the CBD.
“I've gone to court because the actions of the county government are disadvantaging many Kenyans..... before you ban matatus provide an alternative. What happens to children? What happens to the elderly? You have not dealt with security, it is not lit. You have not even created walkways for people, so it is completely unfair and it must be lifted today,” said Mr Sakaja.
The matatu saccos claim that the ban has been effected without adequate notice and that it is being implemented in a haphazard manner.
They allege that the move has ignored public participation and several courts as well as tribunal orders that protects several operators from being hounded out of the city centre.
In their filed case documents, they allege that a Gazette notice on the ban was first issued on May 12, 2017 but its implementation was deferred because there was no public participation.
According to the matatu associations, the shelved Gazette notice was revived on November 29 and has now been effected contrary to the Fair Administration Act.
They also fault the fact that only City Hoppers, City Shuttles, Kenya Bus Services and Double M have been allowed to operate within the CBD because they operate in diametric routes, saying the move is discriminatory.
They allege that the Nairobi Metropolitan Area Transport Authority (NAMATA) should have been involved in the decision.
"The said actions are inconsiderate as there was no study or effort to ascertain whether the designated points can accommodate the number of matatus that are being redirected thus an avenue for chaos," said Mr Duncan Okatch, the lawyer representing the saccos.
He added: "In special circumstances such as this being city centre, it is important for there to have been public participation as the suffering they would be subjected to would be dire."
The Nairobi Transport and Safety Authority as well the National Police Service have also been sued.
They also want that Gazette notice and the ban quashed as well as for the sued parties to be barred from impounding matatus and the ones already seized released immediately.