The Institute of General Practice Management has estimated that the rise will mean the average GP surgery's tax bill will go up by around £20,000 a year. This could end up costing GPs an estimated £125.5m a year in additional costs, for all 6,275 GP practices in England.

This is the equivalent cost of providing 2.24 million GP appointments, at £56 per appointment. It means it could cost the average GP surgery the equivalent of 357 appointments a year.

In response, the Liberal Democrats is seeking to use amendments to upcoming legislation on the Budget to exempt GPs from the National Insurance tax rise. 

Health and Social Care spokesperson, Helen Morgan, said: ‘Clobbering GP practices with higher taxes makes no sense at a time when many people are already struggling to get an appointment.

'Surgeries are already struggling and these increased costs will leave GPs with no choice but to cut services and staff numbers. Ultimately it is patients around the country who will pay the price. The Chancellor needs to urgently rethink these proposals and exempt GPs from this misguided tax hike.'

Ruth Rankine, director of primary care at the NHS Confederation, added: 'We are very worried about the impact the employer national insurance contribution uplift could have on the primary care sector if it must be paid out of GPs' own budgets.

'We are hearing reports that some primary care providers could face eye-watering annual costs on top of already very low financial settlements. This could have dramatic impact on capacity, with practices potentially having no choice but to close or to cut back on their services as they cannot afford to keep them running.'