Birkenhead MP Frank Field has called on a local GP surgery to ring the changes and scrap their high rate telephone number to cut the cost to patients.
He claimed they were being charged 41p a minute to make an appointment at the Fender Way Health Centre in Noctorum.
Describing the premium rate line as a "rip-off", Mr Field is demanding answers about how much patients have been charged to subsidise the practice since the 0844 telephone number was introduced.
He wrote to the practice: “You are the only practice in Merseyside that still uses a higher rate 0844 telephone number for patients to call about an appointment, meaning they are have to pay extra to subsidise the practice.
“Does this not violate the fundamental practice of the NHS being a service that is universally free at the point of use?
“Might I ask whether you have any plans to switch to a cheaper telephone number, and if not why not?”
Practice manager Sharon Joy said today she had no comment to make until the contents of the MPs letter has been discussed with GPs at the health centre.
But the practice’s website contains the following statement: “After listening to the comments with regards to the practice 0844 telephone number, the issue has been addressed by providing an additional telephone number."
It says this is along side 0844 number but does not replace it.
Mr Field pointed out that in April 2010 there was a contractual obligation placed on general practices requiring them to take all reasonable steps to bring their higher rate telephone numbers to an end.
Since then every other GP across Merseyside has done so.
The MP has been campaigning in recent months for the abolition of higher-rate 0845 numbers in government department, including benefit and pension calls to the Department for Work and Pensions.