NHS England has run the scheme to subsidise costs for GPs working for out-of-hours and 111 services since 2015. In 2015 and 2016 it was backed with £5m, while for 2017 funding increased to £10m.
This current scheme runs from 1 October 2017 until 2 April 2018 - offering cover for the cost of professional indemnity for any additional out-of-hours or unscheduled work taken on by GPs if this is not provided by the employer.
But BMA leaders say pressure on the NHS - and high out-of-hours indemnity costs - will not end with winter. Unless the scheme is extended, the available out-of-hours workforce will drop sharply from April, the union warns.
A BMA survey of more than 500 GPs found that four out of five work out-of-hours sessions, and that 63% had carried out extra sessions during the period covered by the winter scheme.
Of GPs working out-of-hours, 82% said indemnity support was a major factor in their decision to take on extra work, and 80% said they would reduce sessions or stop working out-of-hours entirely if the scheme was not extended beyond 2 April. More than two thirds had not booked out-of-hours sessions beyond April.
GPC deputy chair Dr Mark Sanford-Wood said: 'What’s clear from this study is that GPs want to work out-of-hours sessions so they can provide the best possible care for their patients. However, their ability to do this is being put at risk as the winter indemnity scheme comes to an end.
'GPs already face a huge financial burden in the face of rising indemnity fees which are even more inflated for out-of-hours work. This added expense to cover them for out-of-hours services often proves unaffordable and prevents shifts being filled and desperately needed doctors from attending patients at these times.'
An NHS England spokeswoman said: 'NHS England has invested £110m supporting GPs with rising and additional indemnity costs, ensuring these don’t stand in the way of doctors being able to offer patients appointments when most needed.
'This includes both during normal working hours and through the winter indemnity scheme, the busy winter out of hours period, which this year was extended to include the coming Easter bank holiday weekend.'
The £110m figure cited by NHS England includes £20m over three years for the winter scheme, plus £30m for 2016/17 indemnity costs and £60m made available through the latest contract deal for 2017/18.