The City of London plans to move the three historic markets Billinsgate, Smithfields and new Spitalfields to a single site in the capital by 2025.
The four potential boroughs to house the 100-acre wholesale venue are Barking and Dagenham, Redbridge, Newham and Waltham Forest.
Billingsgate fish market started on the bank of Thames in the 16th century before moving to its current site in Poplar in 1982.
Back in 1908, Billingsgate was selling about 400 metric tons of fish per day, while today it sells around 250 metric tons per week.
The proposed schemes to join all three markets under one roof need Parliamentary approval to go through. In the meantime, property consultancy Lambert Smith Hampton was appointed to search for the new site.