King issues first statement since diagnosis, with Palace and Downing Street keen to show he is still carrying out constitutional duties

Buckingham Palace and Downing Street were keen to demonstrate that King Charles remains in close contact with the government on Wednesday, even as he recovers from his first session of cancer treatment.

No 10 took the unusual step of confirming that Rishi Sunak would be telephoning the king in the evening after an agreement with the palace to disclose the information.

The prime minister’s official spokesperson said: “We don’t in general and we are not going to get into the habit of commenting on the PM’s conversations with the king. But we have agreed with the palace in this specific instance to confirm that they will be speaking on the phone later.”

Initially it was speculated that the formal weekly audience between head of state and prime minister, normally held in person and part of the monarch’s core constitutional duties, would be conducted over the phone.

However, a palace source later clarified it would be a personal call for the prime minister to wish Charles well and a speedy recovery, rather than an audience.

No audience had been scheduled for the next fortnight, partly in keeping with the pattern set by the late Queen Elizabeth II for this time of year, and also to allow the king to recover from his benign prostate enlargement procedure.

It is expected that on 21 February formal in-person audiences will resume, subject to any overseas commitments the prime minister may have.

Late on Wednesday the king issued his first public statement since his cancer diagnosis, as he marked Grenada’s 50th anniversary of independence from Britain.

He said: “I can only say how sorry I am that I cannot be with you in person to mark this momentous milestone … My thoughts are with everyone across Grenada, Carriacou and Petit Martinique, and all those in the Grenadian diaspora – ’one people, one family’ – as you celebrate everything you have achieved and all that your future holds. My family join me in sending our heartfelt congratulations to you all.”