This comes a day after seven firms signed a contract worth Sh60 billion in an agreement with City Hall on Monday for the construction expected to last 24 months.
Starehe MP Maina Kamanda threatened to lead a mass demonstration if the county failed to hold fresh talks with tenants.
Tenants of old buildings set for demolition to pave the way for new houses in Nairobi County have dared the developers to evict them.
Tenants from the five estates of Jeevanjee, Bachelor Quarters, Pangani, Old and New Ngara vowed to block the project by the Nairobi County government until fresh negotiations started.
The tenants should have been involved in the agreement with the contractors, he said.
“Nobody will come and start construction in my constituency without us endorsing the project and having an agreement,” said Mr Kamanda.
According to the MP, the county did not show any goodwill during the negotiations when they started “threatening to terminate their contracts and it was obvious that they wanted to benefit from it”.
Mr Kamanda urged the residents to hire lawyers when fresh negotiations start to ensure been left homeless once the project is complete.
Jeevanjee Resident Association chairman Patrick Musau said the last time the county talked to them was in October 3, 2015 when they met and disagreed on the compensation of the tenants.
The county, said Mr Musau, kept changing the narrative and did not want to commit in writing.
“At first, we would be told sweet words and met in boardrooms and no minutes were taken. Later, they were informed that was public participation and their input was never put into consideration,” said Mr musau.
He said City Hall had said it would build on the open spaces where tenants will move to and the old units would be demolished. However, later, they were informed that contractors said they would not work in an area with tenants.
Ngara MCA Mwaura Chege said they were not against the project but the lack of communication from City Hall had caused panic among the tenants.
Other ageing estates targeted are Bahati, Mbotela, Ziwani, Makongeni, Kaloleni, Jericho and Shauri Moyo.
Currently, the county government collects rent from 14,000 houses.