A 100,000-strong petition has been handed in to parliament in protest at plans to close the Portland Coastguard helicopter base.
The Dorset site is expected to close in 2017.
The Government said modern helicopters operating from fewer bases could provide a more reliable service.
The petition stated: "Petitioners believe that there may be lives lost as a result of losing this search and rescue facility."
The petition requests the House of Commons "urges the Department for Transport to reverse the decision to close Portland coastguard helicopter base".
Rescue services will be centralised at a new Maritime Operations Centre in Fareham in three years time.
The Conservative MP for South Dorset Richard Drax, who has led the campaign against the closure, said: "Our fight to retain the helicopter continues."
Search and rescue operations are currently provided by the Ministry of Defence (MoD), which uses Sea King helicopters from eight military bases, and the Maritime and Coastguard Agency (MCA), which operates from four civilian bases.
The government hopes to "improve levels of service while reducing costs", and said the current set-up dated back 40 years and "cannot stand still".
Coastguard stations will also close as a result of the centralised centre - Solent station in Hampshire and Portland in Dorset will close in September, Brixham in Devon will shut in November.
Walton-on-the-Naze in Essex and Crosby in Merseyside are also designated for closure.
The new Maritime Operations Centre in Segensworth, will be run alongside nine other 24-hour centres around the UK.