The annual event is an important fixture in the royal calendar and will see Charles follow the ancient tradition of distributing Maundy money to community stalwarts on Thursday.

It is understood the Queen, who has been experiencing mobility issues, was unable to commit to the event and, with the order of service being printed, she was keen for the arrangements to be confirmed to avoid any misunderstanding or the day to be overshadowed.

The monarch attended a service commemorating the life of the Duke of Edinburgh last week with senior royals and a congregation of hundreds, and has been carrying out virtual events and her other duties as head of state. It is understood she will mark the first anniversary of his death on Saturday privately.

The Queen seen leaving the Service of Thanksgiving for Prince Philip on 29 March

The 95-year-old monarch reached her Platinum Jubilee in February and overcame a bout of Covid after testing positive that month.

After spending a night in hospital last October she spent the following three months under doctors’ orders to only conduct light duties and missed a number of prominent events.

On four occasions a member of the royal family has stood in for the Queen at the Royal Maundy service.

Just a few years into her reign the Lord High Almoner, Michael Gresford Jones the Bishop of St Albans, represented the Queen in 1954, when she was on her extensive Commonwealth tour.

Six years later the Queen Mother stood in for her daughter who had given birth to the Duke of York in February 1960, almost two months before the service, and in 1964 the birth of the Earl of Wessex in March that year meant the Queen’s role was fulfilled by her aunt Princess Mary.

In 1970 the Queen Mother distributed the Maundy money on behalf of the Queen who was on tour in New Zealand.

Charles and Camilla will join the congregation for the Royal Maundy service at St George’s Chapel, Windsor Castle, and will be welcomed by the Right Reverend David Conner who gave the address at Philip’s memorial service.

Following tradition they will be presented with nosegays – sweet smelling bouquets – which in centuries past were used to ward off unpleasant smells during the ceremony.

For the past two years the service has not been held due to the pandemic and instead the Queen wrote to recipients of Maundy money, who received the coins in the post, to thank them for their community work which earned them their nominations.

This year Charles will distribute the Maundy coins to 96 men and 96 women – as the Queen will be 96 this year, celebrating her birthday on April 21.

Each recipient receives two purses, one red and one white.

The white purse is filled with uniquely minted Maundy money – silver 10p and 3p pieces – to the value of 96 pence.

In the red pouch is a £5 coin and a 50p coin portraying the Queen’s Platinum Jubilee. Both coins have been newly minted this year.

The Royal Maundy is an ancient ceremony which originated in the commandment Christ gave after washing the feet of his disciples the day before Good Friday.

Queen 'regretfully' pulls out of attending annual Maundy Day service