Neath Assembly Member Gwenda Thomas has since written to the actor Sir Anthony Hopkins - who features in Barclays' current advertising campaign - pointing out that the branch's survival is vital to efforts to regenerate the local economy.
Several members of the National Assembly have signed an official notice condemning the bank's plans to close another 10 branches in Wales.
Barclays' slim-down of its Welsh branches has already provoked much protest.
At Gwaen-cae-Gurwen in the Swansea Valley, businesses were furious at the loss of the town's last banking facilities.
Neath Assembly Member Gwenda Thomas has since written to the actor Sir Anthony Hopkins - who features in Barclays' current advertising campaign - pointing out that the branch's survival is vital to efforts to regenerate the local economy.
"We're here in an Objective One area and the aim of that, of course, is to regenerate communities like this," she said.
"For an organisation such as Barclays to take a decision to pull out goes against the whole concept of regeneration."
Over the last few years, the main high street banks have closed about 100 branches around Wales, saying the growing use of telephone and online banking is the reason.
'Exporting jobs out of Wales'
In addition to this latest round of cuts by Barclays, similar plans by Lloyds and the National Westminster banks will see the closure of a further 30 local branches.
Steve Pantak of the banking union, UNIFI, said Barclays and Nat West were failing the economy of Wales.
"In the case of Barclays and Nat West, we're seeing many branches close and various jobs being stripped out of the remaining branches.
"They are effectively exporting jobs out of Wales."
The union said it expected the next round of closures to follow towards the end of the year.