Olly Robbins, who was Britain's Brexit negotiator when Theresa May was PM, was fired as the most senior civil servant at the Foreign Office by Sir Keir in April this year.
The Prime Minister, speaking in Motherwell, made clear his support for Scotland remaining part of the UK as he offered 'deeper' devolution to the country.
Andy Burnham will use a summit next month designed to draw the UK closer to the bloc to get a new deal that includes access to its migrant and criminal databases that was lost after Brexit.