In his first address to the public since Princess Diana revealed that she is undergoing chemotherapy, King Charles will emphasize the importance of friendship, “especially during a time when you are in need”.

The Queen will deliver the pre-recorded monarch’s message at the Royal Maundy Service in Worcester Cathedral, Thursday.

He will talk about how Jesus is an “example for how we should care and serve each other” and that as a country “we benefit and need those who extend a hand of friendship to our nation, especially during a time when we are in need”.

The King does not directly refer to the health of his son-in-law and daughter-in law, but it is clear that he acknowledges the difficulties they have had over the last few months.

He says that friendship and kindness have also helped him and his patients deal with their diagnosis and treatment.

Since they announced their cancer diagnosis, Charles and Kate both received a flood of well-wishes.

The Princess was described as “extremely touched” by the support that she received after her emotional video where she revealed that she had started a preventative chemotherapy course.

The King said last month that he was moved to tears when he read the many messages and cards of encouragement he received.

Charles’s words serve to remind us that online speculations about Kate’s condition have been counterproductive.

After relocating from the public eye to recover following major abdominal surgery, she was subjected for weeks to conspiracy theories regarding her location and condition.

The palace said that the King is “so proud of” the Princess for her courage to speak out and that he has “the closest relationship with his beloved daughter in law”.

The 75-year old, who has only been on the throne for 18 months, will also reiterate his Coronation promise “not to be serv’d but to serve”.

In his short personal message recorded in mid-March the King will describe Maundy Money recipients as “wonderful, inspiring examples of kindness”, “giving so much time to serve others in their community”.

He also recorded a Bible Reading that will be heard today by the dozens who attend.

Charles, dressed in a suit and sitting at his desk while recording his message in the 18th Century Room of Buckingham Palace.

Two microphones were ready to record his words and a vase of spring flowers.

While undergoing outpatient treatment, the King has taken a break from his large-scale duties.

In recent weeks, he’s increased his private engagements.

Sources close to King say that “treatment is proceeding well”, and add: “Both doctors as well as patient remain optimistic.”

The King had a private meeting with Mohamed Nasheed at Buckingham Palace on Wednesday. On Tuesday, he hosted an event of religious leaders.

He has decided to stay away from today’s Royal Maundy Service due to health concerns.

The King will lead his Royal family at the Easter Sunday church service in St George’s Chapel at Windsor, his first major event after his cancer diagnosis.

In order to minimize his exposure to others, fewer royals than usual will attend.

The Royal Maundy Service is an important fixture in the royal calendar. The monarch, as the head of the Church of England presents coins specially minted to those who have done community service.

This ceremony commemorates Jesus’ Last Supper, when he washed his disciples’ feet as an act humility on the day before Good Friday.

Today, sovereigns do not wash the feet as they used to in medieval times, but instead, 75 women and men, each representing the age of the King, will receive two purses, red and white, both filled with Maundy Money.

Charles II began the Maundy Money Ceremony in 1662 by giving out coins.

The anti-monarchy Republic group will protest outside Worcester Cathedral.