A Royal Marine could lead the armed forces for the first time as the next Chief of The Defence Staff is due to be selected, according to The Times.
The paper has reported that the decision for the next CDS is between General Sir Gordon Messenger, a Royal Marine who is currently vice-chief of the defence staff, and General Sir Nicholas Carter, Head of the Army.
The Prime Minister will conduct her interviews for the position in the new year so the announcement is expected over the next few weeks.
The appointment of a new CDS normally happens in November, however this year it has been delayed due to the sudden departure of Sir Michael Fallon.
Gavin Williamson, the current Defence Secretary, will signal his preferred choice before a shortlist goes to Mrs May.
Sir Stuart is due to step down in the spring and become chairman of the NATO military committee.