The Prince of Wales has warned that cancer is in danger of becoming ‘the Forgotten C’ as thousands miss out on life-saving treatments due to the coronavirus pandemic.

He added that delayed operations are causing “despair” among patients living with the disease.

Writing for The Telegraph the prince, who is the patron of Macmillan Cancer Support, said: "In many cases, due to the pandemic, difficulties have become crises, a sense of isolation has become actual separation, and – as vital treatment or surgery has in some cases been postponed – anxiety has become despair.

"Macmillan has been adapting to this ever-evolving situation to ensure that cancer does not become 'the Forgotten C' during the pandemic but, even so, Covid-19 has still taken a devastating toll, with the charity losing a third of its fundraised income."

His words come after NHS hospitals were forced to postpone cancer operations as Covid spread across wards, with an estimated 33,000 people in the UK who should have started treatment being left in limbo.

Macmillan - who are predicted to lose £175 million over the next three years after being forced to cancel fundraising events - revealed up to 50,000 people could be living with undiagnosed cancer as a result of NHS delays.

This figure could double to 100,000 by this time next year if authorities fail to fully restore vital cancer health services — including check-ups, screening and referrals — that have been cancelled or paused as a result of coronavirus.

One study estimated between 7,000 and 18,000 excess cancer deaths within the year because of Covid.

Prince Charles explained that receiving a cancer diagnosis and going through treatment could be a frightening experience for patients, even during non-coronavirus times.

He urged the public to think of everyone affected by cancer, whose "own momentous, personal struggles" have been made all the heavier by the pandemic.

"These are truly daunting circumstances. However, a charity set up to tackle cancer is not easily daunted and, as we have seen throughout this last year, right across our country the formidable will and compassion of the British people have outshone every darkness," he added.