Around a quarter of evening and weekend GP appointments are going unfilled in England, an investigation has found.
Out-of-hours appointments have been available in parts of the country since 2014 and NHS England said all surgeries should provide the facility from October 1 this year.
But Pulse magazine discovered, through the Freedom of Information Act, that around half a million evening and weekend appointment slots have been left empty.
The data, from 80 clinical commissioning groups (CCGs), shows 37% of Sunday appointments go unfilled, 24% on Saturdays and 23% on weekday evenings.
In Kent, Thanet CCG saw only 3% of Sunday appointments being booked since April.
British Medical Association GP Committee chairman Dr Richard Vautrey said: "Because it has become a political must-do, everybody is jumping. We understand there is huge pressure from the centre on CCGs to demonstrate they are providing a full seven-day service.
"Sensible CCGs that want to use their resources in a better way are under pressure to maintain a service that really isn't good value for money.
"That is ridiculous so I think we really do need to see much more common sense and pragmatic flexibility.
"If we had the luxury of resource and workforce then we could look at extending the service but until then we've got to focus on what is most important."
NHS England told the magazine: "Even though six out of 10 CCGs didn't respond to this small survey, the more representative results of the annual GP survey and the patient response to new digital-first GP providers is clear: patients want quicker access to a trusted GP both during the working week and outside traditional surgery hours, and are increasingly prepared to vote with their feet to get it."
Copyright (c) Press Association Ltd. 2018, All Rights Reserved. Picture (c) Anthony Devlin / PA Wire.