The branch of HSBC in Risca is to close, the company has confirmed.
The bank has blamed a decrease in footfall as the reason behind the closure.
Islwyn MP Chris Evans said the planned closure of the Tredegar Street branch, on June 3 this year, will be bad news for the town.
Customers will be expected to travel to Blackwood, Cwmbran or Newport for their nearest HSBC branch.
Mr Evans has written to the bank expressing his concern that elderly customers, and those without internet access, will have to travel further to manage their money.
The MP also expressed concern that customers are being advised they will still be able to access banking services from a branch of the Post Office, formerly at 64 Tredegar Street, which no longer exists. Risca Post office is now based at the Spar supermarket on the same street.
Mr Evans said: “I am deeply concerned about the effect the closure of the Risca branch of the HSBC will have on the town. I do not feel that online or telephone banking services are a suitable replacement for speaking face to face with someone at their local branch.
“Although some services will still be available from the local Post Office, it is already very busy in its role as a supermarket without also being used as a bank. It is not a realistic or suitable alternative to a HSBC branch in the town.
“I do not believe that HSBC has properly considered the impact the branch closure will have on Risca and the local community. This is why I have written to HSBC asking them to reconsider the branch closure.”
A HSBC spokesman said: “We never take the decision to close a branch lightly, and we understand it’s unsettling for the local community.
“Unfortunately, with an increase in the use of online and telephone banking over the past few years use of the Risca branch has fallen significantly, and we’ve taken the difficult decision to close it.
“We are working with customers who use the branch to help them understand their options, which include being able to use the local post office for their day-to-day banking. There are also free ATMs in the area.”
The spokesman added that in overall terms, 93% of contact with the bank is now completed via the telephone, internet or smartphone, plus 97% of cash withdrawals are made via an ATM.
The bank, which also closed its Bargoed branch in 2014, will also close its branches in Caldicot, Usk and Ebbw Vale.