The Queen will miss the Commonwealth Heads of Government Meeting for the first time since 1973, Sky News has learned.
Sources say Prince Charles is set to be announced as the member of the royal family to attend the meeting on her behalf in Sri Lanka later this year.
It is unclear why the Queen, who is the Head of the Commonwealth, has chosen not to attend, but many will see the decision as part of a move to transfer some responsibilities to her heir.
The British monarch was admitted to hospital earlier this year suffering from the symptoms of gastroenteritis, but it is not known whether this decision has been made on health grounds.
And unless the CHOGM event is staged in Britain in 2015, many will ask whether the Queen, who by then will be 89, is likely to attend another such meeting in her lifetime.
The leaders of 54 Commonwealth nations meet every two years to discuss and agree collectively on global issues. The Queen attended the last CHOGM meeting in Perth, Australia, in 2011.
Last year saw younger generations of the royal family represent the Queen overseas as part of her Diamond Jubilee celebrations.
Buckingham Palace is likely to suggest Prince Charles’ presence in Sri Lanka is simply a continuation of the wider family’s increased role.
But some are likely to predict this development will pave the way for the Prince of Wales becoming the next Head of the Commonwealth, despite the role not passing automatically to the Queen’s eldest son.
It also follows comments from Australia’s Prime Minister, Julia Gillard, supporting Charles taking over the Commonwealth role despite preferring to move to a republic once the Queen is no longer on the throne.
“For Australia’s part, I am sure the Queen’s successor as monarch will one day serve as head of the Commonwealth with the same distinction as Her Majesty has done,” Ms Gillard said in March.
In a television message recorded in Cape Town on her 21st birthday, the then Princess Elizabeth told the Commonwealth: “I declare before you all that my whole life, whether it be long or short, be devoted to your service and the service of our great imperial family to which we all belong.”
The Queen’s non-attendance at the November meeting is not however thought to be linked to sensitivities surrounding Sri Lanka’s human rights record which has led Canada’s Prime Minister Stephen Harper to boycott the CHOGM.