The Labour MP said it was “vital for local residents, and its potential closure would significantly impact our community”
One resident who responded to the petition said all three banks where they had accounts in Cosham High Street had already closed.
They said this meant they shopped using cash which they were able to withdraw from their bank account via the Post Office.
“The closure of this branch would be disastrous for us elderly people,” they said.
Another retired pensioner who responded to Ms Martin’s petition said they visited the Post Office “nearly every day” to top up their electric key.
They said: “Losing the Post Office would mean losing my daily routine of exercise and social interaction with others.
“The only alternative would be to rely on my phone which doesn’t provide the same level of engagement.”
Ms Martin said she planned to “do everything possible to prevent the closure of this beloved local branch”.