Edited sentence: Ombudsman has filed a suit against the Mayor of Sendai to prevent construction fees from becoming approved.Proponents maintain that the new subway line is necessary to prevent urban sprawl, will decrease the city's environmental load by encouraging use of public transportation, and is based upon adequate estimates.The East-West line has been criticized for being excessively costly, based upon extremely optimistic estimates, and hostile to the natural environment.The suit is pending at the Sendai district courts