Negotiations over doctors' pension reforms could reopen after GPs and hospital doctors staged their first industrial action in almost 40 years.
The British Medical Association (BMA) said it was willing to get back round the table with the Government following Thursday's action.
Dr Hamish Meldrum, chairman of council at the BMA, said doctors have sent a "strong message" to ministers that a better deal on pensions must be found.
Figures showed the action hit almost a fifth of GP practices. In some areas of England, 26% of GP surgeries would see only those patients in urgent need of care. Across the country, 2,703 operations were postponed and 18,717 outpatient appointments were rescheduled, based on figures from strategic health authorities in England.
The data suggests the action affected services at 21% of GP practices across the country.
In the south of England, 482 practices, or 26%, saw at least one member of staff take action while in the Midlands and the East of England a quarter of GP surgeries operated a reduced service. In the north of England, 23% of GP surgeries took part in the day of action and 11% of practices in London treated only urgent cases.
Meanwhile, the Department of Health claimed just 8% of doctors working in the NHS in England, or 11,500, showed their support.
The BMA announced the day of action last month after it accused ministers of pressing ahead with "totally unjustified" increases in pension contributions and a later retirement age for doctors, even though a deal on pensions was agreed four years ago.
The union postponed all non-urgent work and added that although the action will be disruptive, doctors will ensure patient safety is protected.
The last time doctors took action was in 1975, when consultants suspended goodwill activities and worked to contract over a contractual dispute, and junior doctors worked to a 40-hour week because of dissatisfaction with the progress of contract negotiations.