The opposition wants to expand the current cabinet of 17 to 34 ministers, while the government is pushing for 44.
Previous cabinets have had over 30 ministers.
Last year's elections resulted in a long-running dispute between Mwai Kibaki, the president, and Raila Odinaga, the leader of opposition.
Odinga accused Kibaki of rigging the vote.
The protesters who gathered in the capital, Nairobi believe the increase will make no difference in alleviating the country's economic and social problems.
The protesters also say that the country cannot afford the civil servants needed to support new ministers, who are said to be paid similar wages to European politicians.
Kamanda Mucheke, an officer with the Kenya National Commission of Human Rights, said: "The country is bleeding and we need more money for the reconstruction of the country."
"We can't afford 34 or 44 cabinet ministers."
Shortly after his comments, Mucheke was tear gassed along with Wangari Maathai, a Kenyan environmentalist who won the Nobel Peace Prize in 2004 for campaigns to promote conservation, women's rights and government free from corruption.
The protesters carried signs saying "no more than 24".
A leaflet handed out by the protesters said that "Kenyans are outraged at plans for a a bloated cabinet ... these are irresponsible [and] expensive suggestions given the current economic crisis [in] Kenya".
A policeman said the protesters had been forcibly dispersed because they had not applied for permission to hold a demonstration.