Downing Street confirmed Keir Starmer will be following the spectacle in Washington from No10, arguing that there is a convention that premiers do not attend.
Mr Trump's key advisers are also debating whether to put Sir Keir Starmer 'at the back of the queue' of world leaders invited to Washington after tomorrow's inauguration.
No10 admitted it was 'obviously now right' for Donald Trump's incoming US administration to consider the terms of an agreement to hand over the Indian Ocean archipelago.
Ms Gray, a former senior civil servant, stepped down as the Prime Minister's £170,000 chief of staff in October following reports of a clash with other senior aides.
Since entering No10, Sir Keir has travelled to the US, Germany , France , Italy , Ireland, Belgium, Samoa, Hungary , Azerbaijan , Brazil , the UAE, Saudi Arabia and Cyprus.