A bill winding its way through the Assembly is prompting concern about the state’s use of eminent domain in the potential condemnation of Pfizer Inc.’s Brooklyn factory.

If passed, the bill, introduced by Assemblyman Vito Lopez, a Democrat of Brooklyn, would allow for the state to take control of the company’s 15-acre plant in Williamsburg and develop it into 100% “affordable” housing.

Pfizer plans to shut down the Flushing Avenue plant at the end of this year and cut 600 jobs. The pharmaceutical giant has said it plans to develop a mixed-use project that would include an unspecified amount of “affordable” housing. The plant, situated on the site where Pfizer was founded in 1849, was built in the 1940s.

Mr. Lopez’s legislation would have the state’s housing agency acquire the site, then issue its own request for proposals to create about 1,700 housing units.

The assemblyman’s chief of staff, Stephen Levin, said he blames Pfizer for not specifying how much “affordable” housing it would be willing to build. Mr. Levin said the 6.7-acre Rheingold Brewery site in Bushwick is an example of a similar site that was developed into hundreds of “affordable” housing units.

In a statement, a spokesman for Pfizer said: “Not only is the concept of state-sponsored eminent domain extremely premature at this point and could have implications for development statewide but the legislation’s justification fails to mention affordable housing is one of the key uses already being considered.”

“It is an interesting situation,” a partner at Goldstein, Goldstein, Rikon & Gottlieb who specializes in eminent domain, Michael Rikon, said. He said abuse of eminent domain in New York has been a “horrible trend,” but that the creation of “affordable” housing could be interpreted as “an acceptable public purpose” to justify its use. “The classic examples have been schools, municipal buildings, hospitals, roadways, streets, and firehouses,” he said.

Daniel Goldstein, a spokesman for Develop Don’t Destroy Brooklyn, which has been waging its own battle against the state’s use of eminent domain to clear the way for Forest City Ratner’s Atlantic Yards project, said condemnation of the Pfizer site would be “outrageous.”

“The fact that this grossly mistreats business doesn’t make it any better. If Lopez wants the affordable housing on that site then he should work with Pfizer to get it included in the development and require that they build it on their property,” Mr. Goldstein said.

Other projects that would likely include use of eminent domain in New York City include the $7 billion proposed expansion of Columbia University over the next 25 years and the Bloomberg administration’s $3 billion plan to turn a 75-acre site near Shea Stadium in Queens — known as Willets Point — into a retail and entertainment facility.

An attorney at Kramer Levin who specializes in land use, condemnation, and eminent domain, James Greilsheimer, said eminent domain is the most “totalitarian” tool at the disposal of the government. He said the use of the eminent domain with regards to the Pfizer plant needs to be weighed thoroughly by elected leaders before any decision is made.

“It’s certainly a plus for use of condemnation if it is going to be for affordable housing and if there is need for affordable housing and it can’t be obtained in another way,” Mr. Greilsheimer said. “All the factors need to be weighed if that condemnation is for a public use or more to benefit a private party. And the issue isn’t if the property is taken from a rich person or a poor person.”