The Royal Bank of Scotland (RBS) is to stop its basic bank account customers from using ATMs operated by rival high street banks.Basic bank accounts are often aimed at those on lower incomes and do not have any overdraft facility.Existing basic account customers at RBS and its subsidiary NatWest will lose access to other banks' cash machines "over the next few months", a spokeswoman told the Daily Telegraph."It is unsustainable for us to offer free access to other bank ATMs for basic accounts as we face a charge per bank transaction, which needs to be recovered elsewhere," she said. Banks pay aorund 50p-75p per cash withdrawal from rival's cash machines. "We are fully committed to offering a free basic account for people who may otherwise struggle to access banking services," the RBS spokeswoman said. "These account holders will continue to have free access to one of the largest cash machine networks in the UK."RBS is 84% owned by UK taxpayers following a £20bn investment by the government during the financial crisis.Marie Burton, financial inclusion expert at the watchdog Consumer Focus called the move "a kick in the teeth for many of RBS's most vulnerable customers". "Although there are still nearly a million people without bank accounts, the banking sector has been working hard to steadily reduce this figure," she said."Short-sighted moves like this will only help to reverse the good work that has been done." She added that people living in rural areas deserted by bank branch closures might not have the option of other ATMs nearby.