The resident doctors walked out at 7am on Friday 25 July and are expected to continue the action until 7am on Wednesday 30 July.

In a last-minute appeal, Sir Keir wrote in The Times: ‘The route the BMA Resident Doctors Committee have chosen will mean everyone loses. My appeal to resident doctors is this: do not follow the BMA leadership down this damaging road. Our NHS and your patients need you.'

He added: ‘Behind the headlines are the patients whose lives will be blighted by this decision. The frustration and disappointment of necessary treatment delayed. And worse, late diagnoses and care that risks their long-term health.

‘It's not fair on patients. It's not fair on NHS staff who will have to step in for cover for those taking action. And it is not fair on taxpayers.

‘These strikes threaten to turn back the clock on progress we have made in rebuilding the NHS over the last year, choking off the recovery.'

It comes after the secretary of state for health and social care Wes Streeting sent a personal letter to NHS resident doctors yesterday (24 July), saying: ‘I deeply regret the position we now find ourselves in.'

Streeting said that while he cannot pledge a bigger pay rise, he has been committed to progress to improve doctors' working lives.

He said in talks with the BMA, he had been determined to tackle the ‘arduous' training pathway, and ‘I made it clear that I was prepared to agree actions to reduce the costs you face as a result of training'.

Streeting said he had also been looking at the cost of equipment, food and drink, and 'was prepared to explore how many further training posts could be created – additional to the 1,000 already announced – as early as possible'.