LONDON, United Kingdom ( AFP) — Commonwealth leaders will decide on who should follow Queen Elizabeth II as head of the organisation at their summit this week, Downing Street said on Monday.

Queen Elizabeth, 91, has been the symbolic head of the group of nations since the death of her father king George VI in 1952, though the position is not hereditary.

Her eldest son Prince Charles is heir to the throne in 16 of the 53 Commonwealth member states, which are chiefly territories that used to be part of the former British empire.

British Prime Minister Theresa May’s spokesman declined to say whether she thought the position should go to Charles.

Asked whether May thought Charles, the Prince of Wales, should be the next head, the Downing Street spokesman said: “This is obviously a decision that is taken later in the week, and a decision taken by all the members together.

“I think that all happens on Friday.”

Commonwealth leaders are gathering in London for an executive session on Thursday and will hold a retreat at Windsor Castle, west of the city, on Friday for talks behind closed doors.

Commonwealth Secretary-General Patricia Scotland said the Windsor Castle gathering was a chance for the leaders to talk one-to-one without outside interference.

“On the retreat, the 53 leaders get to go away together with no agenda and just talk about all thethings that they desire to talk about. That enables them to deal with some quite tricky, sensitive issues, but collectively, collegiately and as part of the family,” she told a press conference.

Jeremy Corbyn, the leader of Britain’s Labour main opposition, suggested on BBC television on Sunday that the figurehead role could go to a rotating president.

“The queen clearly is personally very committed to the Commonwealth but after her I think maybe it’s a time to say, well, actually the Commonwealth should decide who its own president is on a rotational basis,” he said.

Asked if he would like to see Charles in the role, Britain’s Foreign Secretary Boris Johnson told the same programme: “That is a matter for the 53”.

Scotland told ITV television on Sunday that the heads of government “will make a decision in whatever way they determine”, sidestepping questions on her personal preference.

Charles’s Clarence House office declined to comment.

Queen Elizabeth has curtailed her long-haul travel and Charles represented her at the 2013 biennial summit in Colombo.