Simon Hart MP and Pembroke Chamber of Trade have met Santander bosses to highlight what a blow to the town the closure of the bank branch will be.
Santander is closing its Main Street branch in May and the next nearest will be in Haverfordwest, 13 miles away.
Local traders got in touch with Mr Hart to ask him to arrange a meeting with the bank to try to get them to change their plans.
"I appreciate Santander engaging with the local traders however they were adamant that the closure is going ahead in May," said Mr Hart.
"We had a full and frank discussion about how Santander's departure from town will have a negative effect on shops and cash flow in the town."