Closing Heathrow in favour of a new hub airport elsewhere would have "devastating" economic consequences and lose up to 70,000 jobs.
According to a report commissioned by the London boroughs of Hounslow and Ealing and Slough Borough Council to investigate the impact of closing London's main airport and relocating it on the other side of the city in the Thames Estuary, the resulting job losses have been wildly understimated.
The research by Parsons Brinkerhof and Berkeley Hanover Consulting revealed the "catalytic" impact of closing Heathrow.
"Losing Heathrow would be disastrous for jobs in Hounslow, for our neighbours in Ealing and Slough and very likely for UK PLC," said Councillor Colin Ellar, deputy leader of Hounslow Council.
"At a time when the UK's economic recovery is in its fragile infancy and needs to be nurtured, it would plunge west London into a new recession from which it might never fully recover."
The study came as the Airports Commission prepared to publish an interim report of shortlisted options for airport expansion in the southeast.
The Thames Estuary proposed by the Mayor of London Boris Johnson has yet to be officially eliminated from the list.
"Thousands of local families depend on Heathrow for their livelihoods and the airport plays a critical role in the local economy. Closing it should not be contemplated," said Councillor Julian Bell, leader of Ealing Council.