Campaigning MP John Healey said he will keep up the pressure against use of 084 telephone numbers, after the Government produced guidance banning them.
The MP for Wentworth and Dearne has submitted Parliamentary Questions asking each government department when they will stop using 0844 and 0845 numbers, which cost callers up to 41p a minute.
He has campaigned against their use by GPs and government departments for two years.
He said: “Every day that passes the poorest people are being ripped off and forced to run up big phone bills because they are making essential calls to government services.
“I have tabled questions to every department asking for a deadline by which they will end the use of these lines.”
The campaigning MP added: “Government departments have been told time and time again that what they are doing is very wrong. They must stop the telephone tax and they must start playing fair.”