The King was listed as taking part in the opening ceremony of Cop27 despite not appearing at the UN climate summit.

Downing Street acknowledged last week that the monarch might have been able to join international delegates in Egypt if Prime Minister Rishi Sunak had been in office earlier in the year.

When Liz Truss was premier, a “unanimous agreement” was reached that the King should not attend after advice was sought by his office from the Government.

The title on the UN Climate Change (UNFCCC) live feed for the start of the summit on Monday read: “Opening Ceremony with interventions from President of the Republic, UN SG, King of the United Kingdom, Leader of UAE”.

The President of Egypt Abdel Fattah El-Sisi, the UN Secretary General Antonio Guterres and UAE President Sheikh Mohamed bin Zayed Al Nahyan all appeared and spoke in person at the Red Sea resort of Sharm El-Sheikh, but there was no appearance – virtual or otherwise – from the British monarch.

Buckingham Palace said there were no plans for the King to address Cop27 by video or any other means, and the position had not changed.

The UNFCCC has yet to comment.

Charles, as the Prince of Wales, spent decades passionately campaigning on green and environmental issues.

It was widely reported that the King, who addressed last year’s Cop26 summit in Glasgow, had hoped to attend in person.

However, it is understood that after seeking the advice of Ms Truss, the then PM, as is customary with royal visits overseas, it was agreed that he would not go.

But a Downing Street spokeswoman said last Thursday of the possibility of Charles attending: “We do recognise that had the Prime Minister been in post earlier, the situation might have been different but it is not logistically feasible at this late stage.”

The King did, however, host a reception at Buckingham Palace on Friday ahead of the conference, welcoming leaders, business figures, environmentalists, Mr Sunak and fashion designer Stella McCartney.

Mr Sunak, who is attending the global gathering after a U-turn, told guests at the Palace the world will experience “more human suffering” if we continue to allow “climate change to ravage our planet”.

In 2021, Charles told Cop26 the world had had enough of talking and commitments needed to be put into practice.

The late Queen delivered a video message at the Cop26 welcoming reception, after pulling out of attending while she rested on doctors’ orders.

She urged world leaders to work together in “common cause” to tackle climate change, and said she hoped the summit’s legacy would be that they recognised “the time for words has now moved to the time for action”.