A post office in the village of Crackington Haven in North Cornwall is among many in rural areas nationwide that is under threat.
Many oppose the closure of rural post offices
Steve Blatt, who has run the business for five years, fears that it is in danger.
He told BBC Radio 4's Today programme a particular problem was the government's planned withdrawal of post office card accounts, which are used by millions to access pensions and
"For the users of the post office card accounts the impact is going to be catastrophic," he said.
"They're going to not be able to control their money in the way that they have grown to love and like.
"As for myself it's another nail in the coffin along with everything else that has gone on - for example the loss of the TV licensing."
But he is keen to fight back. A local campaign has seen paper hearts conveying messages of support being sent to the post office.
"It is so important to keep this post office open for the good of the community," reads one message.
The government argues that the smallest post offices are used by an average of 16 people a week, and that the rural network is currently supported by an annual subsidy of £150m.
But an 80-year-old Crackington Haven local said she feared she would have to move away from the village into a town if Mr Blatt's post office closed.
"It would be a disaster for us really. We would seriously have to think about moving," she said.
"We just couldn't cope with running our lives. It would mean we would have to move to a town and leave all our friends and our way of life for the last 20-something years.
"If we left the village our life would be intolerable."
North Devon Liberal Democrat MP Nick Harvey said the government should take action over the issue.
He said: "Many villages in our rural area have lost many of the amenities that they had - the number of schools have reduced, the bus links have reduced, the shops have reduced.
"In many cases there is only one thing left - a corner office with a post office there, as an essential part of its economic balance.
"If there is hardly any business left for the post office that will undermine the shop and these communities will just become dormitories where people come to sleep but go off elsewhere work and carry out their daily lives."