Minister promises summit on 'cash machine crisis'

In a House of Commons debate, Mr Lewis was repeatedly told that the banking industry had failed to tackle confusion over which machines charged for withdrawals. MPs also warned that free ATMs were impossible to find in many poorer areas.

John McFall, who chaired a Treasury Select Committee investigation last year into fee-charging ATMs, said: "Away from existing branches, free access to cash withdrawals could decline as banks sell or close their existing networks."

The dispute follows a sharp increase in the number of ATMs charging a fee for withdrawals. Link, which runs the cash machine network, said there were 23,931 charging ATMs at the end of last year, up from 20,685 a year previously. The number of free machines fell from 32,463 to 32,355.

Although all major banks and building societies have pledged not to charge customers to use their machines, a number of independent operators have installed thousands of fee-charging ATMs in shops, petrol stations and pubs.

The number of charging machines has also risen because several banks have sold some of their ATMs to the independent operators.

Andrew Smith, the former secretary of state work and pensions, said: "In my Oxford constituency, the fee-charging machines are sited in some of the poorest areas." The Bristol MP Dan Norris added: "Banks are selling off their free cash machines - isn't that just greed?"

Link has introduced rules designed to force cash machine operators to make charges clearer. However, Halifax bank and Nationwide Building Society have launched a campaign for ATMs to carry notices with traffic light-style colour-coding. Green signs would denote free machines, while fee-charging ATMs would have to carry a red sign.

Edwin Latter, Link's card scheme director, said: "We have no desire to see free machines disappear - they represent 96 per cent of all transactions - but this obsession with red and green is frustrating because our new rules already make charges very obvious."