The Government today announced plans to guarantee everyone access to a basic bank account.
Chancellor Alistair Darling said the move would lead to up to one million more people having access to bank accounts during the coming five years.
There are currently around 1.75 million adults who do not have a transactional bank account, more than half of whom are among the poorest fifth of the population, according to a Treasury task force.
But the banking industry said it already offered everyone access to a basic bank account.
It added that it had also exceeded its joint target, set with the Government in 2003, to halve the number of people who did not have an account.
The British Bankers' Association said: "Everybody can have a bank account if they want one, unless, and this is rare, the law says they can't.
"In recent years UK banks have worked with the Government to cut financial exclusion, halving the number of households without a bank account. Every month 40,000 more people open basic accounts."
Basic bank accounts enable people to receive credits, such as wages or benefits, while they can be used to set up direct debits and some accounts also come with a debit card.
But they do not offer a cheque book or overdraft facility, although some accounts have a £10 buffer zone.
All of the major banks offer the accounts, which can be opened by anyone who can prove their identity.
The number of unbanked households fell from 3.57 million in 2003/04 to 1.75 million in 2007/08.
The BBA said if the current rate of decrease continued, the number of unbanked consumers would halve again within five years.
It added that there are now almost 8 million basic bank accounts in existence in the UK.