lifeline
n. countablen. something that helps you survive or succeed when you are in a very difficult situation. It can be a person, a service, or a piece of equipment that saves you.
n. a source of vital assistance or support that enables survival or continued operation during a crisis. In its literal sense, refers to a rope or line used for saving life at sea.
The government grant was a lifeline for the small business.
For many elderly residents living in remote areas, the local bus service is a vital lifeline to the nearest pharmacy.
The emergency credit facility provided a necessary lifeline to the bank, preventing a total collapse of liquidity while the board negotiated a more permanent restructuring plan.
From life + line.
Often used metaphorically with the preposition 'to' or 'for'.