James Evans is set to host a public meeting following the news that Lloyds Bank in Brecon will close next year.
The bank cited fewer people using the branch as the reason for its closure.
Brecon and Radnorshire MS James Evans said he is “bitterly disappointed” following today’s announcement.
“Many elderly customers and vulnerable adults do not have access to online banking and rely heavily on the branch.”
According to Lloyds figures, 59 per cent of its personal customers at the Brecon branch are aged 55 and above.
21 per cent of its customers are 75+.
Mr Evans also said he was concerned for businesses in the area who take cash and need a physical bank for transactions.
“I will be working closely with Lloyds Bank to ensure customers are supported up to and beyond the closure date,” he said.
Mr Evans added: “Continued access to cash is vital, and I will also be working with LINK to ensure that the current ATM cashpoint in the Lloyds Bank building is relocated elsewhere in the town, just as I have in other towns such as Presteigne.
“I will be holding a public meeting to discuss this on Thursday, October 3 at the Castle Hotel in Brecon.”
The MS has said that representatives from Lloyds Bank have been invited to attend.