Mohammad Asghar AM welcomed local campaigner Eric Channing to the Senedd on Wednesday.
After the meeting, Newport-resident Mr Channing went to HSBC in Cardiff to present a petition against the closure of a branch of the bank on Caerleon Road, Newport.
Mr Asghar invited him to the Assembly to give other local Assembly Members the opportunity to offer their support.
The South Wales East AM said: “It has been my pleasure to offer my support to Mr Channing.
“He has campaigned hard and gathered well over 3,200 signatures in opposition to the branch closure.
“I am very concerned by the impact that the loss of the branch and its cash machine will have on many local people and neighbouring businesses.
“I have written to the HSBC to express my concern and hope they reverse this decision”.
