Stephen Byers, the secretary of state for trade and industry, last night told the big banks they should participate in the establishment of the Post Office-based "universal" bank to provide accounts for the poor.
In a summit with the chairmen and chief executives of the banking groups, Mr Byers was believed to have made it clear government money would be made available to help with set-up costs.
Some operators have been critical of the "universal" bank, which is at the core of the government's aim to provide a lifeline to the PO network.
The banks' concerns are based on the potential set-up costs and the operation of the new entity.
They feel it duplicates efforts led by the Treasury to create basic accounts for people without them.
Mr Byers was believed to have used yesterday's meeting as an opportunity to provide details of how the bank would work, using the business plan drawn up by the PO as the basis for his presentation.
The PO wants to set up the bank under a new brand name to try to address some of the banks' concerns about its reputation in the industry.
It also understood that the PO expects the government to inject some cash into the creation of the operation.
The banks last night insisted that they had attended the meeting with an open mind, but the British Bankers' Association has warned that the so-called universal bank could carry the stigma of being a poor people's bank.
