The standard cost of a call to NHS Direct is between 3p and 5p per minute, but people calling from mobiles or non-BT landlines may be charged more.
Asked for an assurance that NHS Direct would not continue with higher rates telephone charges, junior health minister Ivan Lewis told MPs: 'I can give a cast-iron guarantee that it will not be allowed to continue.'
A spokeswoman for NHS Direct recognised that some telephone providers may charge high rates on top of the basic cost of a call to the service.
'We are in discussion with the DoH, which set up the 0845 number in 1997, and we are looking at other options,' she said.
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