Prince Andrew is expected to become Queen Elizabeth's escort at official functions.
The 57-year-old royal will reportedly play a key role in changes to 'Team Windsor' following the announcement his father, 95-year-old Prince Philip, is stepping down from public duties later this year.
After months of planning, it is felt Andrew - the couple's second son and sixth in line to the throne - is best place to step up and join his mother at official engagements where Philip would previously have accompanied his wife.
A source told the Daily Mail newspaper: "[The queen and Andrew] get on very well.
"There is ample precedence already for the Queen doing engagements with people who are not her husband."
Another source said: "Prince Andrew will be doing more high-profile engagements and has already stepped in to accompany the Queen on a number of occasions."
Last month, Andrew joined his 91-year-old mother at a Windsor Castle ceremony, where she honoured the Royal Lancers regiment with a ceremonial flag as a symbol of their loyalty to the monarchy, and in December, he was by her side for a charity reception at Buckingham Palace.
Earlier this year, the queen's grandson, Prince William, revealed he is leaving his job with the East Anglian Air Ambulance Service and will relocate with wife Duchess Catherine and their children Prince George, three, and Princess Charlotte, two, to Kensington Palace later this summer.
And it has now emerged they decided to make the changes as part of the plans for Philip's retirement.
A source said: "When it was announced in January that William was giving up the day job, the Palace was already planning for Prince Philip's retirement."
William and Catherine, along with the prince's younger brother Prince Harry, are now expected to step up the number of official duties they carry out.