In its report 'Local but Limited', it argued that while the model does offer benefits, changes needed to be made to ensure it helps deliver a long-term future for the network.
Post Office Local is a scaled-down service model currently being trialled throughout the network. Rather than a dedicated counter offering Post Office services, it provides a core range of services such as electronic bill payments, foreign currency and banking transactions over the counter.
However, key concerns for Consumer Focus were the limited services available through the scheme, privacy for customers at the checkout, and quality of service.
Consumer Focus post office expert Andy Burrows said it was vital that the Post Office delivered a model that met its customers' needs before it was rolled out further.
"We recognise that the Post Office must change if it is to be successful in the future and PO Locals have the potential to modernise the network, but the design and implementation must be absolutely right for their customers," he said.
National Federation of SubPostmasters (NFSP) general secretary George Thomson defended the scheme, saying that PO Local was a work in progress. "The Post Office Local model is in its trial stages, and the NFSP is working closely with Post Office Ltd to make sure that the model meets the needs of both operators and customers," he said. "We expect the Local model will play a major role in the years ahead in maintaining the network at its current size and making sure Post Office services remain available to communities and small businesses."