Mayor Andy Burnham has unveiled a £7.5 billion homes tax aimed at London.
The levy targets newly built homes and would be tacked onto property costs.
Buyers are already asking for a "Burnham discount" as they factor the tax into offers.
Business groups warn this levy could deter investors away from the capital.
Housing advocates contend the revenue could alleviate the city’s shortage of affordable homes.
Observers observe the proposal may transform regional economic policies and affect how middle‑earners plan home purchases.