Cofek has sued Nairobi County following its move to double parking fees within the central business district from Sh200.
In the suit against Governor Mike Sonko's administration, the Consumer Federation of Kenya said the notice given to the public was too short.
The decision to increase parking fees was made on September 25 under Finance Act, 2019, and is expected to take effect on Wednesday.
Cofek also said the decision was unreasonable, punitive and discriminatory and that pubic participation did not take place.
The lobby further said parking services director Tom Tinega lacked the mandate to set timelines for commencement of Finance Act 2019.
"The purported notice to increase parking fees with effect from December 4 is unreasonable, irrational, unjust and offends the spirit of the Constitution. If implemented, the rights of consumers will be greatly infringed," said Mr Henry Kurauka for Cofek.
"Most vehicle owners will not afford to pay the increased parking charges because of the harsh economic reality."
According to the notice that Mr Tinega issued on Tuesday, motorists in the CBD as well as Kijabe Street will pay Sh400 daily for parking services.
Buses will pay Sh1,000 daily while private vehicles will pay Sh7,000 for a one-month seasonal parking ticket, Sh18,000 for three months, Sh32,000 for six months and Sh55,000 for a year.
Parties that lose parking tickets will pay Sh1,000 per ticket to get another copy of the seasonal ticket.
Motorists have been paying Sh200 daily to park in the city center but the fee has now been divided into three categories, the CBD being Zone 1.
Motorists in Zone II will continue paying Sh200. This includes those in Westlands, Upper Hill, Community, Ngara, Highridge, Industrial Area, Gigiri, Kilimani, Yaya Centre, Allsops, Mwiki, Dagoretti, Kawangware, Kangemi, South B and South C.
This also applies to Nairobi West, Lang'ata, Madaraka, Makadara, Buruburu, Umoja, Kayole, Embakasi, Donholm, Muthaiga, Milimani, Hurlingham, Lavington, Karen and Eastleigh.
For Zone III, which covers all other commercial centers except those in Zones I and II, motorists will continue to pay Sh100.
The county indicated that the higher fee will help address dismal revenue performance in the last financial year.
However, Cofek noted that there was no reasonable infrastructure to ensure alternative and convenient modes of transport, such as a bus rapid transit system.
The lobby also argued that most motorists are forced to pay parking boys for security because the county has failed to provide for this despite collecting the fee.
It further argued that there was no reasonable cause to increase the parking fees as most residents were struggling to meet basic needs.
In the filed case documents, Cofek further alleged that Nairobi had not taken measures to mitigate the suffering of those with special needs or short term engagements in the CBD.
The lobby asked the High Court to temporarily halt implementation of the new parking fees.