A group of Labour MPs have warned the new transport secretary the closure of Doncaster Sheffield Airport (DSA) "will cost lives" due to the move forcing key public services to relocate.
On Monday, Peel Group announced DSA would wind down from 31 October.
In a joint letter to MP Anne-Marie Trevelyan, 11 South Yorkshire MPs told her critical police and search and rescue aeroplanes are based at DSA.
They warn of "grave consequences to national security and human life".
The Department for Transport said Ms Trevelyan will "respond to the letter in full in due course".
The National Police Air Service's four aeroplanes are based at the site, the letter said, with the Maritime and Coastguard Agency and Ministry of Defence also using DSA.