Hundreds of people signed a petition against plans to close the last bank in a busy high street.
Earlier this year it was announced the NatWest branch in High Road, Harrow Weald, will close in July, which led to traders launching a petition.
The bank is the last in the high street and the nearest other branch is more than a mile and a half away in Harrow town centre.
Businesses in the high street have raised concerns about the closure of the branch as many are customers at the bank and want it to remain local.
On Saturday, Labour parliamentary candidate for Harrow East Uma Kumaran collected more than 200 hundred signatures calling for the branch not to close.
She said: “The closure of Harrow Weald’s last bank would be a significant loss to our community and all the local businesses and residents who rely on it.
“I have written to the chief executive of RBS asking him to reconsider the closure.
“There is also a real concern as to what will replace NatWest if they do decide to leave. You only have to look at our high street to know the last thing we need in Harrow is another payday lender or betting shop.
“Unfortunately, the Tory government have made it harder for local councils to protect our high streets from yet more of them appearing.
“I’ve spoken to local traders and residents alike, they’re all calling for the bank to stay and so am I.”
Harrow Borough Councillor Phil O’Dell said: “I am deeply concerned about the impact that NatWest leaving the high street.
“I hope the support we have received from local residents for our campaign will force them to reconsider the closure.”
A spokeswoman for Natwest has told the Harrow Times footfall and transactions at the bank have fallen by 18 per cent in the past few years as people are turning to online banking.
The bank also said it would be taking a number of measures to ensure its customers can access its services via the nearby branch of the Post Office.