Neither the Department of Health nor NHS England know how many GPs will be required to meet patient demand over the next five years due to a lack of reliable data, the National Audit Office has found.

The NAO added that the bodies have a limited understanding of where staffing pressures lie in general practice as they do not have detailed data on the number or use of locum GPs, or substantive GP vacancies.

The public spending watchdog said in a report published today: “Due to the lack of reliable data on the number of [patient] consultations, the Department of Health and NHS England do not know how many more GPs are required to meet demand.

“Nor do they have detailed data on the number or use of locum GPs, or on staff vacancies in general practice. This limits their understanding of where current pressures lie.”

In its election manifesto, the government committed to provide an additional 5,000 doctors in general practice by the end of the parliament to improve patient access.

The report on patient access to general practice also recommended NHS England research how different practices’ working arrangements and appointment-booking systems drive variations in access.

The NAO found large variation between GP practices in the proportion of patients reporting being unable to get an appointment, from 0 per cent in some areas up to 52 per cent.

The office’s own analysis of the 2014-15 GP Patient Survey found that just over a quarter of the variation could be explained by differences in patient demographics, practice staffing, practice list size, rurality or deprivation.

But the body said this implied individual practices’ appointment-booking systems and other working practices played a role in variations in patient access to a GP.

The report states: “NHS England should improve the data it collects on demand and supply in general practice, and research how different practices’ appointment-booking and other working arrangements drive variations in access.

“While making changes designed to improve access, NHS England should analyse the impact on different patient groups.”

An NHS England spokesman said: “Real terms spending on general practice has increased every year since NHS England was established, following two years of decline, and the vast majority of patients have reported a positive experience when accessing general practice.

“This year we are investing an extra £126m to improve access to general practice as well as working closely with our partners to expand the primary care workforce and further benefit patients.”

A Department of Health spokeswoman said: ”This report shows patients want better access to their GP and that’s exactly why we’re providing everyone with evening and weekend appointments by 2020.

“To do that we are making available an estimated 5,000 more doctors in general practice so we have the skills we need to provide that seven day service.”