Responding to the exchange of letters between the British Medical Association and NHS England over derogation requests during the junior doctors' strike, the chief executive of NHS Providers, Sir Julian Hartley, said:

"Trust leaders' number one priority is patient safety.

"They are working flat out with frontline staff to mitigate the impact of strike action in the face of severe winter pressures, currently compounded by a sharp spike in flu and a surge in cases of Covid-19.

"This hard work, backed up by meticulous planning and preparation, is making a real difference.

"But there is no doubting the scale of the challenges they face.

"The timing, scale and duration of the current action has taken these pressures to a new level, and based on their responsibility to protect patient safety, some trusts have asked for derogations.

"These requests are initiated by trust based medical directors, who are senior clinicians acting in good faith.

"They need an escalation process that is timely and allows them to respond proportionately and effectively to keep patients safe in what are often very difficult circumstances."